WWW

同

ウェブ Web

関

HTML

WordNet

1. the 23rd letter of the Roman alphabet (同)w, double-u

PrepTutorEJDIC

1. Watt / West; Western
2. wolfram(=tungsten)の原子記号
3. World War 世界大戦

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2019/08/02 19:06:25」(JST)

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インターネット
Opte Projectによる、インターネットの一部を通したルーティングパスの視覚化
主要項目 アクセス 検閲 - 民主主義 情報格差 デジタル権 情報公開 インターネットの歴史 インターネット現象 ネットワーク中立性 最古のドメイン名 先駆者 プライバシー 社会学 使用率
ガバナンス ICANN Internet Engineering Task Force インターネットガバナンスフォーラム インターネットソサエティ
情報基盤 Domain Name System Hypertext Transfer Protocol インターネットエクスチェンジ Internet Protocol インターネット・プロトコル・スイート インターネットサービスプロバイダ IPアドレス Internet Message Access Protocol Simple Mail Transfer Protocol
サービス ブログ ミニブログ 電子メール Fax ファイル共有 ファイル転送 ゲーム インスタントメッセージ ポッドキャスト ショッピング テレビ VoIP World Wide Web 検索エンジン

ウェブページは、ウェブブラウザーを使用することで閲覧できる。ウェブブラウザは、通常リンク部分に色を付け、下線を引く。また、ウェブページには画像を表示することができる。

2014年時点での各国のウェブ・インデックスを表した世界地図。

World Wide Web（ワールド・ワイド・ウェブ、略名：WWW）とは、インターネット上で提供されているハイパーテキストシステムである。Web、ウェブ、W3（ダブリュー スリー）とも呼ばれる。俗には「インターネット」という表現がワールド・ワイド・ウェブを指す場合もある。情報提供を担う者はウェブサーバを公開し、一般利用者はウェブブラウザを介してウェブサーバにある情報を閲覧するようなシステムが基本である。

概要

ウィキペディアの周辺の World Wide Web をグラフィック表現したもの。複雑ネットワークの一例でもある。

ワールドワイドウェブではドキュメント（ウェブページ）の記述には主にHTMLやXHTMLといったハイパーテキストの記述言語が使用される。ワールドワイドウェブで使われるハイパーテキストとは、文書中に別の文書のURLへの参照を埋め込むことで（これをハイパーリンクと呼ぶ）インターネット上に散在する文書同士を相互に参照可能にするシステムである。閲覧者は表示している文書中でハイパーリンクが付された箇所をクリックやタップなどする事でハイパーリンク先の文書を表示させることができる。

世界中に張り巡らしたような、文書間のつながり方が蜘蛛の巣を連想させることから、世界に広がる蜘蛛の巣を意味する「World Wide Web」と名付けられた。尚、蜘蛛の巣は現実のケーブルの配線を表しているわけではない。HTMLの記述方式は比較的単純なため、急速に広く普及した。

ワールドワイドウェブにアクセスするためのソフトウェア（ユーザーエージェント）は WWW クライアントと呼ばれる。そのうち、利用者による閲覧を目的としたものは特にウェブブラウザ（WWW ブラウザ、あるいは単にブラウザ）と呼ばれる。また、ワールドワイドウェブのサービスを提供するソフトウェアを「WWWサーバソフトウェア」あるいは単に「ウェブサーバ」という。

ポータル検索エンジンとウェブディレクトリの出現により、ワールドワイドウェブは徐々にその真価を発揮し始めた。数学的な理論に基礎付けられたウェブページの順位決定法を実用化することによって、検索エンジンの首座は一気呵成に確定した。それとは対照的に、すべての分野に亘って個々の事例の集積を要するウェブディレクトリの作成は、継続的で地道な作業によって成し遂げられる辞書の編纂と似ている。前者が数学的手法に依存しているのに対し、後者は分類学的手法によっている点が対照的である。

World Wide Webが実装するハイパーテキストの思想はザナドゥ計画に起源を持ち、その仕様はザナドゥ計画の縮小版とも説明される。但し、World Wide Webで実現されたWebアプリやクラウドコンピューティング等は、厳格なルール運用を想定したザナドゥ計画等の前世代のハイパーテキストシステムの思想を遥かに超えている。

歴史

バーナーズ＝リーがCERNで使用していたNeXTcube。最初のWWWサーバとなった。

ハイパーテキストの思想自体は1945年に発表されたMemexと、1959年に開発が開始されたoN Line System、1960年に開始されたザナドゥ計画に起源を持つが、World Wide Webの直接の起源については1980年にティム・バーナーズ＝リーがロバート・カイリューと構築したENQUIRE （エンクワイア）に遡ることができる。その名称は「エンクワイア・ウィズィン・アポン・エブリシング」というビクトリア朝時代の日常生活のハウツー本に由来していて、バーナーズ＝リーが幼少のころを思い出して付けたものである。それは現在のウェブとは大分違うが、根本的なアイデアの多くを含んでおり、更にはバーナーズ＝リーの WWW 後のプロジェクトである セマンティック・ウェブ の考え方をも含んでいた。しかし、ENQUIRE は一般に公表されるまでには至らなかった。

1989年3月12日、欧州原子核研究機構 (CERN) のティム・バーナーズ＝リーは「Information Management: A Proposal」（情報管理: 提案）を執筆し、ENQUIRE を参照しつつさらに進んだ情報管理システムを描いた。彼は1990年11月12日、World Wide Web をより具体化した提案書「WorldWideWeb: Proposal for a HyperText Project」を発表した。実装は1990年11月13日から開始され、バーナーズ＝リーは最初のウェブページを NeXTワークステーション上に置いた。

その年のクリスマス休暇の間に、バーナーズ＝リーは WWW に必要な全ツールを構築した。世界初のウェブブラウザ（ウェブエディタでもある）と世界初のWWWサーバである。

1991年8月6日、彼は World Wide Web プロジェクトに関する簡単な要約をalt.hypertextニュースグループに投稿した。この日がWWWがインターネット上で利用可能なサービスとしてデビューした日である。

ハイパーテキストの概念は1960年代にまで遡ることができる。テッド・ネルソンのザナドゥ計画、ダグラス・エンゲルバートの oN-Line System (NLS) などである。ネルソンもエンゲルバートも、ヴァネヴァー・ブッシュのマイクロフィルムベースの夢の装置 memex の影響を受けたものであり、memex は1945年の論文「As We May Think」で描かれている。

バーナーズ＝リーのブレイクスルーはハイパーテキストとインターネットを結合したことである。彼は著書「Weaving The Web」の中で、このふたつの技術の結合は双方の技術コミュニティの協力によって成立することを強調しているが、誰もこの提案を取り上げることはなく、最終的に自分自身でプロジェクトを実行したのである。この過程で彼はURIと呼ばれるグローバルな資源識別子を開発した。

World Wide Web は当時実現していた他のハイパーテキストシステムとはいくつかの点で異なる。

• WWW は、双方向ではなく単方向のリンクを使用する。これにより、何らかの資源の所有者と連絡を取らなくてもリンクすることが可能となった。これによって WWW サーバやブラウザの実装も簡単になっているが、同時にリンク先の資源がいつの間にか無くなるという問題も発生させることとなる。
• HyperCardやGopherとは違い、World Wide Web は特定の個人や組織によって独占されておらず、サーバやクライアントを独自に開発し拡張するのも自由にできて許諾を得る必要も無い。

開発当初、WWW は文字情報を扱うだけの比較的単純なものであった（NeXT上で開発されたためOS自身が文字以外を適切に扱うため、WWW は情報を区別しなくてもよかったというのが真相）。しかし1992年、イリノイ大学の米国立スーパーコンピュータ応用研究所 (NCSA) によって、現在のように画像なども扱えるようになった。同校の学生であったマーク・アンドリーセンらは文字だけでなく画像なども扱える革新的なブラウザ Mosaic を開発。そしてこのソフトに改良を加えるために無料でソースコードを公開したため、Mosaic はたちまち普及し、WWW は誰でも手軽に使うことのできる世界的なメディアとなった。

1993年4月30日、CERN は World Wide Web を無料で誰にでも開放することを発表した。

1992年9月30日、高エネルギー加速器研究機構所属の森田洋平が、日本最初のホームページを開設した。

社会的影響

ウェブは人類史上最大の規模で個人間の情報交換を可能とした。ウェブを通して、地球全体で多種多様な情報を自由に交換することができるようになったのである。

感情的な経験、政治的考え方、文化習慣、音楽の風習、ビジネスについての助言、芸術、写真、文学などが、人類史上最も安価にデジタル化されて共有・拡散される。ウェブはそれを支える技術と設備の上に成り立っているが、印刷物と違って物理的な形を持たない。そのため ウェブを通じた情報伝播は物理的な量に制限されず、情報を複写するのに大きな手間もかからない。またインターネットを使う利点として、ウェブ上の情報は簡単かつ効率的に検索でき、他のどんな通信手段（郵便、電話など）や実地の旅行よりも早く情報を集めることができる。

すなわちウェブは今まで地上に現れた個人の情報交換媒体としては最も広範囲で遠くまで伝達可能なものである。多くのユーザーが世界各地の人々と情報交換し、他の手段では不可能だったことを可能とするだろう。

ウェブは社会交流を促して、膨大な知識の集積を育み、個々人の地球規模の理解を深める役に立つと示唆する人もいる。一方、多くの人々を仮想世界に閉じこもらせ、好戦性を増大させ、地球規模の管理・支配体制を生み出すのに使われる可能性も持っているとも言われる。

技術

仕組み

ワールドワイドウェブはクライアントサーバモデルに基づくシステムである。

ワールドワイドウェブ上の文書などの資源にアクセスするには、まずウェブブラウザにURIを入力するか、文書のリンクをたどればよい。すると、第一段階としてURIのサーバ名を表す部分がドメイン・ネーム・システム (DNS) と呼ばれるインターネットの分散データベースによってIPアドレスに変換される（IPアドレスが直接指定されている場合はこの変換は行われない）。

次に、そのIPアドレスに対応する WWW サーバに対して、URIのスキーム（通信方法などの指定）に従い接続を試みる。プロトコルとしては主にHTTPが使用される。一般的なウェブページでは、文書を構成するHTMLファイルや画像ファイルが要求され、即座に要求元に転送される。

ウェブブラウザは、受け取ったHTMLファイルやCSSファイルにしたがってレンダリングし、画像をはめ込み、リンクをはめ込むなどの仕事を行う。これによって利用者が見ている画面上の「ページ」が生み出される。

多くのウェブページは他の関連する文書へのハイパーリンクを含んでいる。それは例えばダウンロードのページだったり、ソース文書だったり、他の定義だったり、ワールドワイドウェブ上の何かの資源だったりする。このハイパーリンクによって情報の網（ウェブ）が形成される。これによってワールドワイドウェブが構成されているのである。

標準規格

ワールドワイドウェブを構成する根本的な標準規格が3つ存在する。

• Uniform Resource Locator (URL) または Uniform Resource Identifier (URI) は、ウェブページのようなWWW上の資源を参照するための汎用のシステムである。
• Hypertext Transfer Protocol (HTTP) は、ブラウザとサーバの通信方法を指定したものである。
• HyperText Markup Language (HTML) は、ハイパーテキスト文書の構造と内容を定義している。

これらは当初すべてIETFのRFCにより標準化が進められていた。その後、ワールドワイドウェブ特有の技術、HTMLなどは非営利組織である World Wide Web Consortium (W3C) によって標準化が進められることになった。現在、バーナーズ＝リーはW3Cを指導する立場である。W3Cは上記を含めた様々な標準を開発・保守し、ワールドワイドウェブ上のコンピュータが様々な形態の情報を格納してやりとりできるよう尽力している。

それに加え、WHATWGが登場し、2019年現在、上記3技術の標準化は、それぞれ以下の組織が行っている。

• URLおよびURI: IETFおよびWHATWG
• HTTP: IETF
• HTML: W3CおよびWHATWG

JavaScript

JavaScript はウェブページのために開発された、クライアント側のスクリプト言語である。ネットスケープコミュニケーションズが開発したものである。名前の一部に「Java」を含んではいるが、技術的には Java との関係はほとんどない。文法はC言語に似ている。オブジェクト指向的にコーディングする以外に手続き的にコーディングすることもできる。

HTMLとJavaScriptを組み合わせて動的にウェブページを書き換える手法は、静的なウェブページと区別するためにダイナミックHTML(DHTML)と表現されることが多い。JavaScriptで動的にウェブページを書き換えるという発想は、ウェブページの装飾のみに使える程度の価値しか持たないとされていた。しかし、2005年2月18日に起きたAjaxの提唱と普及により、ネイティブアプリケーションと変わらない操作性を持つウェブアプリケーションにまで発展した。

アプレットとプラグイン

ウェブの普及期の初期にはサン・マイクロシステムズの Java技術により、小さなプログラム（アプレット）を直接WWWサーバが提供する情報に埋め込むウェブページが登場した。のちにマクロメディアのFlashとそのプラグインが登場すると、Javaアプレットに取って代わった。アプレットやFlashプラグインを利用したプログラムはクライアント側のコンピュータ上で動作し、高速で豊かなユーザインタフェースを可能とした。

Flashプラグインは2000年代に爆発的な普及をみせ、一時期はほぼ全てのウェブブラウザが初期状態で搭載するほどだったが、2010年代に入るとJavaScriptを応用したウェブアプリケーションの発展に押され、Flashプラグインを利用するウェブページは減少した。今日では古い技術となったJavaアプレットやFlashプラグインはセキュリティリスクと見なされ、ウェブブラウザから取り除かれる傾向にある。

統計

2001年の研究によれば、ウェブ上の文書は5500億個以上も存在し、その多くは「深層Web」にあるという。

2002年の20億以上のウェブページを調査した結果によると、英語のコンテンツが56.4%で最も多く、以下、ドイツ語 (7.7%) 、フランス語 (5.6%) 、日本語 (4.9%) となっていた。これ以降、中国語のページの増加が目立っている。

2005年1月では、75種類の言語でウェブ検索を行ってサンプリングし、一般に検索可能なWebは少なくとも115億ページ存在するとの結果を得ている。

2006年2月では、静的なページだけでも150億ページ以上、動的に生成されるページを含めると350億ページ以上が存在するとの推定がある。

雑学

「インターネット・サーフィン」という言葉は1992年6月に出版された「ウィルソン・ライブラリー・ビュレッティン」の中のジーン・アーマー・ポリー（司書）の書いた文章から発祥しているという。ポリーは独自にこの言葉を生み出したかもしれないが、1991年から1992年にかけて Usenet で同様の言葉が散見された。更にそれ以前にハッカーのコミュニティで使われていたという証言もある。

英語では、「worldwide」と一語で表記するのが普通だが、「World Wide Web」やその略記の「WWW」英語でも普通に使われるようになった。最初の頃は、単語を連続して書いて単語の先頭だけを大文字にした 「WorldWideWeb」（インターキャップとかキャメルケースといわれ、プログラマが好む命名規則）とか、ハイフンが入った 「World-Wide Web」（英語の本来の使用法に近い）と表記されることも多かった。

英語では「World Wide Web（ワールド・ワイド・ウェブ）」より「WWW（ダブリュー・ダブリュー・ダブリュー）」の略称が一般的である。ただし、皮肉なことに、「WWW」の方が「World Wide Web」よりも音節数が多く、発音するのにかえって時間がかかる。バーナーズ＝リーによれば、他の人はそれを理由に名前を変えるように助言したが、バーナーズ＝リー本人がこの名称に固執したとのことである。

英語圏の多くの地域では、「WWW」は「ダブリュー・ダブリュー・ダブリュー」と発音されるが、ニュージーランドでは「ダブ・ダブ・ダブ」と発音されることが多い。

関連項目

• ウェブサイト
• コーポレートサイト
• Webプログラミング
• コンテンツ管理システム (CMS)
• セマンティック・ウェブ
• 検索エンジン
• ウェブディレクトリ
• ウェブマイニング
• ハイパーテキスト
• ストリーミング
• Web 2.0 - これはWWWが単なるWebサイトの集合体からWebアプリケーションを提供するプラットフォームへと変化していくことを表す用語として使われる。

外部リンク

• 最初のウェブサイト （英語）
• 日本最初のホームページ
• WWW黎明期の歴史と立役者
• ウェブ工学の研究室
• ASCII.jpデジタル用語辞典『World Wide Web』 - コトバンク
• デジタル大辞泉『ワールドワイドウェブ』 - コトバンク

標準規格

以下は、World Wide Web の基本的な3つの標準規格を定義した文書のリストである。

• Uniform Resource Identifier (URI)
  • RFC 3986, Uniform Resource Identifier (URI): Generic Syntax
  • WHATWG URL Stdanrd
• HyperText Markup Language (HTML)
  • W3C HTML 5.2
  • WHATWG HTML Standard
• Hypertext Transfer Protocol (HTTP)
  • RFC 7230, Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
  • RFC 7231, Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content
  • RFC 7232, Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests
  • RFC 7233, Hypertext Transfer Protocol (HTTP/1.1): Range Requests
  • RFC 7234, Hypertext Transfer Protocol (HTTP/1.1): Caching
  • RFC 7235, Hypertext Transfer Protocol (HTTP/1.1): Authentication
  • RFC 7540, Hypertext Transfer Protocol Version 2 (HTTP/2)

wiki en

[Wiki en表示]

"WWW" and "The Web" redirect here. For other uses of WWW, see WWW (disambiguation). For other uses of web, see Web (disambiguation).

For the first web software, see WorldWideWeb.

Not to be confused with the Internet.

A web page can be displayed using a web browser. Web browsers often highlight and underline hypertext links and web pages can contain images.

A global map of the web index for countries in 2014

The World Wide Web (WWW), commonly known as the Web, is an information system where documents and other web resources are identified by Uniform Resource Locators (URLs, such as https://www.example.com/), which may be interlinked by hypertext, and are accessible over the Internet. The resources of the WWW may be accessed by users by a software application called a web browser.

English scientist Tim Berners-Lee invented the World Wide Web in 1989. He wrote the first web browser in 1990 while employed at CERN near Geneva, Switzerland. The browser was released outside CERN in 1991, first to other research institutions starting in January 1991 and then to the general public in August 1991. The World Wide Web has been central to the development of the Information Age and is the primary tool billions of people use to interact on the Internet.

Web resources may be any type of downloaded media, but web pages are hypertext media that have been formatted in Hypertext Markup Language (HTML). Such formatting allows for embedded hyperlinks that contain URLs and permit users to navigate to other web resources. In addition to text, web pages may contain images, video, audio, and software components that are rendered in the user's web browser as coherent pages of multimedia content.

Multiple web resources with a common theme, a common domain name, or both, make up a website. Websites are stored in computers that are running a program called a web server that responds to requests made over the Internet from web browsers running on a user's computer. Website content can be largely provided by a publisher, or interactively where users contribute content or the content depends upon the users or their actions. Websites may be provided for a myriad of informative, entertainment, commercial, governmental, or non-governmental reasons.

History

Main article: History of the World Wide Web

The NeXT Computer used by Tim Berners-Lee at CERN.

The corridor where WWW was born. CERN, ground floor of building No.1

Tim Berners-Lee's vision of a global hyperlinked information system became a possibility by the second half of the 1980s. By 1985, the global Internet began to proliferate in Europe and the Domain Name System (upon which the Uniform Resource Locator is built) came into being. In 1988 the first direct IP connection between Europe and North America was made and Berners-Lee began to openly discuss the possibility of a web-like system at CERN.

While working at CERN, Berners-Lee became frustrated with the inefficiencies and difficulties posed by finding information stored on different computers. On March 12, 1989, he submitted a memorandum, titled "Information Management: A Proposal", to the management at CERN for a system called "Mesh" that referenced ENQUIRE, a database and software project he had built in 1980, which used the term "web" and described a more elaborate information management system based on links embedded as text: "Imagine, then, the references in this document all being associated with the network address of the thing to which they referred, so that while reading this document, you could skip to them with a click of the mouse." Such a system, he explained, could be referred to using one of the existing meanings of the word hypertext, a term that he says was coined in the 1950s. There is no reason, the proposal continues, why such hypertext links could not encompass multimedia documents including graphics, speech and video, so that Berners-Lee goes on to use the term hypermedia.

With help from his colleague and fellow hypertext enthusiast Robert Cailliau he published a more formal proposal on 12 November 1990 to build a "Hypertext project" called "WorldWideWeb" (one word) as a "web" of "hypertext documents" to be viewed by "browsers" using a client–server architecture. At this point HTML and HTTP had already been in development for about two months and the first Web server was about a month from completing its first successful test. This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve "the creation of new links and new material by readers, [so that] authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him/her has become available". While the read-only goal was met, accessible authorship of web content took longer to mature, with the wiki concept, WebDAV, blogs, Web 2.0 and RSS/Atom.

The CERN data centre in 2010 housing some WWW servers

The proposal was modelled after the SGML reader Dynatext by Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University. The Dynatext system, licensed by CERN, was a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime, but it was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community, namely a fee for each document and each document alteration. A NeXT Computer was used by Berners-Lee as the world's first web server and also to write the first web browser, WorldWideWeb, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the first web browser (which was a web editor as well) and the first web server. The first web site, which described the project itself, was published on 20 December 1990.

The first web page may be lost, but Paul Jones of UNC-Chapel Hill in North Carolina announced in May 2013 that Berners-Lee gave him what he says is the oldest known web page during a 1991 visit to UNC. Jones stored it on a magneto-optical drive and on his NeXT computer. On 6 August 1991, Berners-Lee published a short summary of the World Wide Web project on the newsgroup alt.hypertext. This date is sometimes confused with the public availability of the first web servers, which had occurred months earlier. As another example of such confusion, several news media reported that the first photo on the Web was published by Berners-Lee in 1992, an image of the CERN house band Les Horribles Cernettes taken by Silvano de Gennaro; Gennaro has disclaimed this story, writing that media were "totally distorting our words for the sake of cheap sensationalism".

The first server outside Europe was installed at the Stanford Linear Accelerator Center (SLAC) in Palo Alto, California, to host the SPIRES-HEP database. Accounts differ substantially as to the date of this event. The World Wide Web Consortium's timeline says December 1992, whereas SLAC itself claims December 1991, as does a W3C document titled A Little History of the World Wide Web. The underlying concept of hypertext originated in previous projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University, Ted Nelson's Project Xanadu, and Douglas Engelbart's oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush's microfilm-based memex, which was described in the 1945 essay "As We May Think".

Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally assumed the project himself. In the process, he developed three essential technologies:

• a system of globally unique identifiers for resources on the Web and elsewhere, the universal document identifier (UDI), later known as uniform resource locator (URL) and uniform resource identifier (URI);
• the publishing language Hypertext Markup Language (HTML);
• the Hypertext Transfer Protocol (HTTP).

The World Wide Web had several differences from other hypertext systems available at the time. The Web required only unidirectional links rather than bidirectional ones, making it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot. Unlike predecessors such as HyperCard, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the server implementation of the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular web browser was ViolaWWW for Unix and the X Window System.

Robert Cailliau, Jean-François Abramatic, and Tim Berners-Lee at the 10th anniversary of the World Wide Web Consortium.

Scholars generally agree that a turning point for the World Wide Web began with the introduction of the Mosaic web browser in 1993, a graphical browser developed by a team at the National Center for Supercomputing Applications at the University of Illinois at Urbana–Champaign (NCSA-UIUC), led by Marc Andreessen. Funding for Mosaic came from the US High-Performance Computing and Communications Initiative and the High Performance Computing Act of 1991, one of several computing developments initiated by US Senator Al Gore. Prior to the release of Mosaic, graphics were not commonly mixed with text in web pages and the web's popularity was less than that of older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol. The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October 1994. It was founded at the Massachusetts Institute of Technology Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency (DARPA), which had pioneered the Internet; a year later, a second site was founded at INRIA (a French national computer research lab) with support from the European Commission DG InfSo; and in 1996, a third continental site was created in Japan at Keio University. By the end of 1994, the total number of websites was still relatively small, but many notable websites were already active that foreshadowed or inspired today's most popular services.

Connected by the Internet, other websites were created around the world. This motivated international standards development for protocols and formatting. Berners-Lee continued to stay involved in guiding the development of web standards, such as the markup languages to compose web pages and he advocated his vision of a Semantic Web. The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularising use of the Internet. Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet. The Web is an information space containing hyperlinked documents and other resources, identified by their URIs. It is implemented as both client and server software using Internet protocols such as TCP/IP and HTTP. Berners-Lee was knighted in 2004 by Queen Elizabeth II for "services to the global development of the Internet". He never patented his invention.

Function

Main articles: HTTP and HTML

The World Wide Web functions as an application layer protocol that is run "on top of" (figuratively) the Internet, helping to make it more functional. The advent of the Mosaic web browser helped to make the web much more usable, to include the display of images and moving images (GIFs).

The terms Internet and World Wide Web are often used without much distinction. However, the two terms do not mean the same thing. The Internet is a global system of interconnected computer networks. In contrast, the World Wide Web is a global collection of documents and other resources, linked by hyperlinks and URIs. Web resources are accessed using HTTP or HTTPS, which are application-level Internet protocols that use the Internet's transport protocols.

Viewing a web page on the World Wide Web normally begins either by typing the URL of the page into a web browser, or by following a hyperlink to that page or resource. The web browser then initiates a series of background communication messages to fetch and display the requested page. In the 1990s, using a browser to view web pages—and to move from one web page to another through hyperlinks—came to be known as 'browsing,' 'web surfing' (after channel surfing), or 'navigating the Web'. Early studies of this new behaviour investigated user patterns in using web browsers. One study, for example, found five user patterns: exploratory surfing, window surfing, evolved surfing, bounded navigation and targeted navigation.

The following example demonstrates the functioning of a web browser when accessing a page at the URL http://www.example.org/home.html. The browser resolves the server name of the URL (www.example.org) into an Internet Protocol address using the globally distributed Domain Name System (DNS). This lookup returns an IP address such as 203.0.113.4 or 2001:db8:2e::7334. The browser then requests the resource by sending an HTTP request across the Internet to the computer at that address. It requests service from a specific TCP port number that is well known for the HTTP service, so that the receiving host can distinguish an HTTP request from other network protocols it may be servicing. The HTTP protocol normally uses port number 80 and for HTTPS protocol it normally is port number 443. The content of the HTTP request can be as simple as two lines of text:

GET /home.html HTTP/1.1
Host: www.example.org

The computer receiving the HTTP request delivers it to web server software listening for requests on port 80. If the web server can fulfil the request it sends an HTTP response back to the browser indicating success:

HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8

followed by the content of the requested page. HyperText Markup Language (HTML) for a basic web page might look like this:

<html>
  <head>
    <title>www.Example.org – The World Wide Web</title>
  </head>
  <body>
    <p>The World Wide Web, abbreviated as WWW and commonly known ...</p>
  </body>
</html>

The web browser parses the HTML and interprets the markup (<title>, <p> for paragraph, and such) that surrounds the words to format the text on the screen. Many web pages use HTML to reference the URLs of other resources such as images, other embedded media, scripts that affect page behaviour, and Cascading Style Sheets that affect page layout. The browser makes additional HTTP requests to the web server for these other Internet media types. As it receives their content from the web server, the browser progressively renders the page onto the screen as specified by its HTML and these additional resources.

HTML

Main article: HTML

Hypertext Markup Language (HTML) is the standard markup language for creating web pages and web applications. With Cascading Style Sheets (CSS) and JavaScript, it forms a triad of cornerstone technologies for the World Wide Web.

Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for the appearance of the document.

HTML elements are the building blocks of HTML pages. With HTML constructs, images and other objects such as interactive forms may be embedded into the rendered page. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes and other items. HTML elements are delineated by tags, written using angle brackets. Tags such as <img /> and <input /> directly introduce content into the page. Other tags such as <p> surround and provide information about document text and may include other tags as sub-elements. Browsers do not display the HTML tags, but use them to interpret the content of the page.

HTML can embed programs written in a scripting language such as JavaScript, which affects the behavior and content of web pages. Inclusion of CSS defines the look and layout of content. The World Wide Web Consortium (W3C), maintainer of both the HTML and the CSS standards, has encouraged the use of CSS over explicit presentational HTML since 1997.

Linking

Most web pages contain hyperlinks to other related pages and perhaps to downloadable files, source documents, definitions and other web resources. In the underlying HTML, a hyperlink looks like this: <a href="http://www.example.org/home.html">www.Example.org Homepage</a>

Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks

Such a collection of useful, related resources, interconnected via hypertext links is dubbed a web of information. Publication on the Internet created what Tim Berners-Lee first called the WorldWideWeb (in its original CamelCase, which was subsequently discarded) in November 1990.

The hyperlink structure of the WWW is described by the webgraph: the nodes of the web graph correspond to the web pages (or URLs) the directed edges between them to the hyperlinks. Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This makes hyperlinks obsolete, a phenomenon referred to in some circles as link rot, and the hyperlinks affected by it are often called dead links. The ephemeral nature of the Web has prompted many efforts to archive web sites. The Internet Archive, active since 1996, is the best known of such efforts.

WWW prefix

Many hostnames used for the World Wide Web begin with www because of the long-standing practice of naming Internet hosts according to the services they provide. The hostname of a web server is often www, in the same way that it may be ftp for an FTP server, and news or nntp for a Usenet news server. These host names appear as Domain Name System (DNS) or subdomain names, as in www.example.com. The use of www is not required by any technical or policy standard and many web sites do not use it; the first web server was nxoc01.cern.ch. According to Paolo Palazzi, who worked at CERN along with Tim Berners-Lee, the popular use of www as subdomain was accidental; the World Wide Web project page was intended to be published at www.cern.ch while info.cern.ch was intended to be the CERN home page, however the DNS records were never switched, and the practice of prepending www to an institution's website domain name was subsequently copied. Many established websites still use the prefix, or they employ other subdomain names such as www2, secure or en for special purposes. Many such web servers are set up so that both the main domain name (e.g., example.com) and the www subdomain (e.g., www.example.com) refer to the same site; others require one form or the other, or they may map to different web sites. The use of a subdomain name is useful for load balancing incoming web traffic by creating a CNAME record that points to a cluster of web servers. Since, currently, only a subdomain can be used in a CNAME, the same result cannot be achieved by using the bare domain root.

When a user submits an incomplete domain name to a web browser in its address bar input field, some web browsers automatically try adding the prefix "www" to the beginning of it and possibly ".com", ".org" and ".net" at the end, depending on what might be missing. For example, entering 'microsoft' may be transformed to http://www.microsoft.com/ and 'openoffice' to http://www.openoffice.org. This feature started appearing in early versions of Firefox, when it still had the working title 'Firebird' in early 2003, from an earlier practice in browsers such as Lynx. It is reported that Microsoft was granted a US patent for the same idea in 2008, but only for mobile devices.

In English, www is usually read as double-u double-u double-u. Some users pronounce it dub-dub-dub, particularly in New Zealand. Stephen Fry, in his "Podgrams" series of podcasts, pronounces it wuh wuh wuh. The English writer Douglas Adams once quipped in The Independent on Sunday (1999): "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for". In Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching to wàn wéi wǎng (万维网), which satisfies www and literally means "myriad dimensional net", a translation that reflects the design concept and proliferation of the World Wide Web. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalised, with no intervening hyphens. Use of the www prefix has been declining, especially when Web 2.0 web applications sought to brand their domain names and make them easily pronounceable.

As the mobile Web grew in popularity, services like Gmail.com, Outlook.com, Myspace.com, Facebook.com and Twitter.com are most often mentioned without adding "www." (or, indeed, ".com") to the domain.

Scheme specifiers

The scheme specifiers http:// and https:// at the start of a web URI refer to Hypertext Transfer Protocol or HTTP Secure, respectively. They specify the communication protocol to use for the request and response. The HTTP protocol is fundamental to the operation of the World Wide Web, and the added encryption layer in HTTPS is essential when browsers send or retrieve confidential data, such as passwords or banking information. Web browsers usually automatically prepend http:// to user-entered URIs, if omitted.

Web page

Main article: Web page

A screenshot of a web page on Wikimedia Commons

A web page (also written as webpage) is a document that is suitable for the World Wide Web and web browsers. A web browser displays a web page on a monitor or mobile device.

The term web page usually refers to what is visible, but may also refer to the contents of the computer file itself, which is usually a text file containing hypertext written in HTML or a comparable markup language. Typical web pages provide hypertext for browsing to other web pages via hyperlinks, often referred to as links. Web browsers will frequently have to access multiple web resource elements, such as reading style sheets, scripts, and images, while presenting each web page.

On a network, a web browser can retrieve a web page from a remote web server. The web server may restrict access to a private network such as a corporate intranet. The web browser uses the Hypertext Transfer Protocol (HTTP) to make such requests to the web server.

A static web page is delivered exactly as stored, as web content in the web server's file system. In contrast, a dynamic web page is generated by a web application, usually driven by server-side software. Dynamic web pages help the browser (the client) to enhance the web page through user input to the server.

Static web page

Main article: Static web page

A static web page (sometimes called a flat page/stationary page) is a web page that is delivered to the user exactly as stored, in contrast to dynamic web pages which are generated by a web application.

Consequently, a static web page displays the same information for all users, from all contexts, subject to modern capabilities of a web server to negotiate content-type or language of the document where such versions are available and the server is configured to do so.

Dynamic web pages

Main articles: Dynamic web page and Ajax (programming)

Dynamic web page: example of server-side scripting (PHP and MySQL).

A server-side dynamic web page is a web page whose construction is controlled by an application server processing server-side scripts. In server-side scripting, parameters determine how the assembly of every new web page proceeds, including the setting up of more client-side processing.

A client-side dynamic web page processes the web page using HTML scripting running in the browser as it loads. JavaScript and other scripting languages determine the way the HTML in the received page is parsed into the Document Object Model, or DOM, that represents the loaded web page. The same client-side techniques can then dynamically update or change the DOM in the same way.

A dynamic web page is then reloaded by the user or by a computer program to change some variable content. The updating information could come from the server, or from changes made to that page's DOM. This may or may not truncate the browsing history or create a saved version to go back to, but a dynamic web page update using Ajax technologies will neither create a page to go back to, nor truncate the web browsing history forward of the displayed page. Using Ajax technologies the end user gets one dynamic page managed as a single page in the web browser while the actual web content rendered on that page can vary. The Ajax engine sits only on the browser requesting parts of its DOM, the DOM, for its client, from an application server.

DHTML is the umbrella term for technologies and methods used to create web pages that are not static web pages, though it has fallen out of common use since the popularization of AJAX, a term which is now itself rarely used. Client-side-scripting, server-side scripting, or a combination of these make for the dynamic web experience in a browser.

JavaScript is a scripting language that was initially developed in 1995 by Brendan Eich, then of Netscape, for use within web pages. The standardised version is ECMAScript. To make web pages more interactive, some web applications also use JavaScript techniques such as Ajax (asynchronous JavaScript and XML). Client-side script is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse movements or clicks, or based on elapsed time. The server's responses are used to modify the current page rather than creating a new page with each response, so the server needs only to provide limited, incremental information. Multiple Ajax requests can be handled at the same time, and users can interact with the page while data is retrieved. Web pages may also regularly poll the server to check whether new information is available.

Website

The usap.gov website

Main article: website

A website is a collection of related web resources including web pages, multimedia content, typically identified with a common domain name, and published on at least one web server. Notable examples are wikipedia.org, google.com, and amazon.com.

A website may be accessible via a public Internet Protocol (IP) network, such as the Internet, or a private local area network (LAN), by referencing a uniform resource locator (URL) that identifies the site.

Websites can have many functions and can be used in various fashions; a website can be a personal website, a corporate website for a company, a government website, an organization website, etc. Websites are typically dedicated to a particular topic or purpose, ranging from entertainment and social networking to providing news and education. All publicly accessible websites collectively constitute the World Wide Web, while private websites, such as a company's website for its employees, are typically a part of an intranet.

Web pages, which are the building blocks of websites, are documents, typically composed in plain text interspersed with formatting instructions of Hypertext Markup Language (HTML, XHTML). They may incorporate elements from other websites with suitable markup anchors. Web pages are accessed and transported with the Hypertext Transfer Protocol (HTTP), which may optionally employ encryption (HTTP Secure, HTTPS) to provide security and privacy for the user. The user's application, often a web browser, renders the page content according to its HTML markup instructions onto a display terminal.

Hyperlinking between web pages conveys to the reader the site structure and guides the navigation of the site, which often starts with a home page containing a directory of the site web content. Some websites require user registration or subscription to access content. Examples of subscription websites include many business sites, news websites, academic journal websites, gaming websites, file-sharing websites, message boards, web-based email, social networking websites, websites providing real-time stock market data, as well as sites providing various other services. End users can access websites on a range of devices, including desktop and laptop computers, tablet computers, smartphones and smart TVs.

Web browser

Main article: Web browser

A web browser (commonly referred to as a browser) is a software user agent for accessing information on the World Wide Web. To connect to a website's server and display its pages, a user needs to have a web browser program. This is the program that the user runs to download, format and display a web page on the user's computer.

In addition to allowing users to find, displaying and moving between web pages, a web browser will usually have features like keeping bookmarks, recording history, managing cookies (see below) and home pages and may have facilities for recording passwords for logging into web sites.

The most popular browsers are Chrome, Firefox, Safari, Internet Explorer, and Edge.

Web server

Main article: Web server

The inside and front of a Dell PowerEdge web server, a computer designed for rack mounting

A Web server is server software, or hardware dedicated to running said software, that can satisfy World Wide Web client requests. A web server can, in general, contain one or more websites. A web server processes incoming network requests over HTTP and several other related protocols.

The primary function of a web server is to store, process and deliver web pages to clients. The communication between client and server takes place using the Hypertext Transfer Protocol (HTTP). Pages delivered are most frequently HTML documents, which may include images, style sheets and scripts in addition to the text content.

Multiple web servers may be used for a high traffic website; here, Dell servers are installed together being used for the Wikimedia Foundation.

A user agent, commonly a web browser or web crawler, initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so. The resource is typically a real file on the server's secondary storage, but this is not necessarily the case and depends on how the web server is implemented.

While the primary function is to serve content, a full implementation of HTTP also includes ways of receiving content from clients. This feature is used for submitting web forms, including uploading of files.

Many generic web servers also support server-side scripting using Active Server Pages (ASP), PHP (Hypertext Preprocessor), or other scripting languages. This means that the behaviour of the web server can be scripted in separate files, while the actual server software remains unchanged. Usually, this function is used to generate HTML documents dynamically ("on-the-fly") as opposed to returning static documents. The former is primarily used for retrieving or modifying information from databases. The latter is typically much faster and more easily cached but cannot deliver dynamic content.

Web servers can also frequently be found embedded in devices such as printers, routers, webcams and serving only a local network. The web server may then be used as a part of a system for monitoring or administering the device in question. This usually means that no additional software has to be installed on the client computer since only a web browser is required (which now is included with most operating systems).

HTTP (web) cookie

Main article: HTTP cookie

An HTTP cookie (also called web cookie, Internet cookie, browser cookie, or simply cookie) is a small piece of data sent from a website and stored on the user's computer by the user's web browser while the user is browsing. Cookies were designed to be a reliable mechanism for websites to remember stateful information (such as items added in the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, logging in, or recording which pages were visited in the past). They can also be used to remember arbitrary pieces of information that the user previously entered into form fields such as names, addresses, passwords, and credit card numbers.

Cookies perform essential functions in the modern web. Perhaps most importantly, authentication cookies are the most common method used by web servers to know whether the user is logged in or not, and which account they are logged in with. Without such a mechanism, the site would not know whether to send a page containing sensitive information, or require the user to authenticate themselves by logging in. The security of an authentication cookie generally depends on the security of the issuing website and the user's web browser, and on whether the cookie data is encrypted. Security vulnerabilities may allow a cookie's data to be read by a hacker, used to gain access to user data, or used to gain access (with the user's credentials) to the website to which the cookie belongs (see cross-site scripting and cross-site request forgery for examples).

Tracking cookies, and especially third-party tracking cookies, are commonly used as ways to compile long-term records of individuals' browsing histories – a potential privacy concern that prompted European and U.S. lawmakers to take action in 2011. European law requires that all websites targeting European Union member states gain "informed consent" from users before storing non-essential cookies on their device.

Google Project Zero researcher Jann Horn describes ways cookies can be read by intermediaries, like Wi-Fi hotspot providers. He recommends to use the browser in incognito mode in such circumstances.

Search engine

Main article: Search engine

The results of a search for the term "lunar eclipse" in a web-based image search engine

A web search engine or Internet search engine is a software system that is designed to carry out web search (Internet search), which means to search the World Wide Web in a systematic way for particular information specified in a web search query. The search results are generally presented in a line of results, often referred to as search engine results pages (SERPs). The information may be a mix of web pages, images, videos, infographics, articles, research papers and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler. Internet content that is not capable of being searched by a web search engine is generally described as the deep web.

Deep web

Main article: Deep web

The deep web, invisible web, or hidden web are parts of the World Wide Web whose contents are not indexed by standard web search engines. The opposite term to the deep web is the surface web, which is accessible to anyone using the Internet. Computer scientist Michael K. Bergman is credited with coining the term deep web in 2001 as a search indexing term.

The content of the deep web is hidden behind HTTP forms, and includes many very common uses such as web mail, online banking, and services that users must pay for, and which is protected by a paywall, such as video on demand, some online magazines and newspapers, among others.

The content of the deep web can be located and accessed by a direct URL or IP address, and may require a password or other security access past the public website page.

Web caching

A web cache is a server computer located either on the public Internet, or within an enterprise that stores recently accessed web pages to improve response time for users when the same content is requested within a certain time after the original request. Most web browsers also implement a browser cache by writing recently obtained data to a local data storage device. HTTP requests by a browser may ask only for data that has changed since the last access. Web pages and resources may contain expiration information to control caching to secure sensitive data, such as in online banking, or to facilitate frequently updated sites, such as news media. Even sites with highly dynamic content may permit basic resources to be refreshed only occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. Enterprise firewalls often cache Web resources requested by one user for the benefit of many users. Some search engines store cached content of frequently accessed websites.

Web security

For criminals, the Web has become a venue to spread malware and engage in a range of cybercrimes, including identity theft, fraud, espionage and intelligence gathering. Web-based vulnerabilities now outnumber traditional computer security concerns, and as measured by Google, about one in ten web pages may contain malicious code. Most web-based attacks take place on legitimate websites, and most, as measured by Sophos, are hosted in the United States, China and Russia. The most common of all malware threats is SQL injection attacks against websites. Through HTML and URIs, the Web was vulnerable to attacks like cross-site scripting (XSS) that came with the introduction of JavaScript and were exacerbated to some degree by Web 2.0 and Ajax web design that favours the use of scripts. Today by one estimate, 70% of all websites are open to XSS attacks on their users. Phishing is another common threat to the Web. In February 2013, RSA (the security division of EMC) estimated the global losses from phishing at $1.5 billion in 2012. Two of the well-known phishing methods are Covert Redirect and Open Redirect.

Proposed solutions vary. Large security companies like McAfee already design governance and compliance suites to meet post-9/11 regulations, and some, like Finjan have recommended active real-time inspection of programming code and all content regardless of its source. Some have argued that for enterprises to see Web security as a business opportunity rather than a cost centre, while others call for "ubiquitous, always-on digital rights management" enforced in the infrastructure to replace the hundreds of companies that secure data and networks. Jonathan Zittrain has said users sharing responsibility for computing safety is far preferable to locking down the Internet.

Privacy

Main article: Internet privacy

Every time a client requests a web page, the server can identify the request's IP address and usually logs it. Also, unless set not to do so, most web browsers record requested web pages in a viewable history feature, and usually cache much of the content locally. Unless the server-browser communication uses HTTPS encryption, web requests and responses travel in plain text across the Internet and can be viewed, recorded, and cached by intermediate systems. Another way to hide personally identifiable information is by using a VPN. A VPN encrypts online traffic and masks original IP address lowering the chance of user identification. When a web page asks for, and the user supplies, personally identifiable information—such as their real name, address, e-mail address, etc.—web-based entities can associate current web traffic with that individual. If the website uses HTTP cookies, username and password authentication, or other tracking techniques, it can relate other web visits, before and after, to the identifiable information provided. In this way it is possible for a web-based organisation to develop and build a profile of the individual people who use its site or sites. It may be able to build a record for an individual that includes information about their leisure activities, their shopping interests, their profession, and other aspects of their demographic profile. These profiles are obviously of potential interest to marketeers, advertisers and others. Depending on the website's terms and conditions and the local laws that apply information from these profiles may be sold, shared, or passed to other organisations without the user being informed. For many ordinary people, this means little more than some unexpected e-mails in their in-box or some uncannily relevant advertising on a future web page. For others, it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome. Law enforcement, counter terrorism, and espionage agencies can also identify, target and track individuals based on their interests or proclivities on the Web.

Social networking sites try to get users to use their real names, interests, and locations, rather than pseudonyms, as their executives believe that this makes the social networking experience more engaging for users. On the other hand, uploaded photographs or unguarded statements can be identified to an individual, who may regret this exposure. Employers, schools, parents, and other relatives may be influenced by aspects of social networking profiles, such as text posts or digital photos, that the posting individual did not intend for these audiences. On-line bullies may make use of personal information to harass or stalk users. Modern social networking websites allow fine grained control of the privacy settings for each individual posting, but these can be complex and not easy to find or use, especially for beginners. Photographs and videos posted onto websites have caused particular problems, as they can add a person's face to an on-line profile. With modern and potential facial recognition technology, it may then be possible to relate that face with other, previously anonymous, images, events and scenarios that have been imaged elsewhere. Due to image caching, mirroring and copying, it is difficult to remove an image from the World Wide Web.

Standards

Main article: Web standards

Web standards include many interdependent standards and specifications, some of which govern aspects of the Internet, not just the World Wide Web. Even when not web-focused, such standards directly or indirectly affect the development and administration of web sites and web services. Considerations include the interoperability, accessibility and usability of web pages and web sites.

Web standards, in the broader sense, consist of the following:

• Recommendations published by the World Wide Web Consortium (W3C)
• "Living Standard" made by the Web Hypertext Application Technology Working Group (WHATWG)
• Request for Comments (RFC) documents published by the Internet Engineering Task Force (IETF)
• Standards published by the International Organization for Standardization (ISO)
• Standards published by Ecma International (formerly ECMA)
• The Unicode Standard and various Unicode Technical Reports (UTRs) published by the Unicode Consortium
• Name and number registries maintained by the Internet Assigned Numbers Authority (IANA)

Web standards are not fixed sets of rules, but are a constantly evolving set of finalized technical specifications of web technologies. Web standards are developed by standards organizations—groups of interested and often competing parties chartered with the task of standardization—not technologies developed and declared to be a standard by a single individual or company. It is crucial to distinguish those specifications that are under development from the ones that already reached the final development status (in case of W3C specifications, the highest maturity level).

Accessibility

Main article: Web accessibility

There are methods for accessing the Web in alternative mediums and formats to facilitate use by individuals with disabilities. These disabilities may be visual, auditory, physical, speech-related, cognitive, neurological, or some combination. Accessibility features also help people with temporary disabilities, like a broken arm, or ageing users as their abilities change. The Web receives information as well as providing information and interacting with society. The World Wide Web Consortium claims that it is essential that the Web be accessible, so it can provide equal access and equal opportunity to people with disabilities. Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect." Many countries regulate web accessibility as a requirement for websites. International co-operation in the W3C Web Accessibility Initiative led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology.

Internationalisation

The W3C Internationalisation Activity assures that web technology works in all languages, scripts, and cultures. Beginning in 2004 or 2005, Unicode gained ground and eventually in December 2007 surpassed both ASCII and Western European as the Web's most frequently used character encoding. Originally RFC 3986 allowed resources to be identified by URI in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set—and now a resource can be identified by IRI in any language.

See also

• Electronic publishing
• Internet metaphors
• Internet security
• Lists of websites
• Prestel
• Streaming media
• Web development tools
• Web literacy
• World Wide Telecom Web

Further reading

• Berners-Lee, Tim; Bray, Tim; Connolly, Dan; Cotton, Paul; Fielding, Roy; Jeckle, Mario; Lilley, Chris; Mendelsohn, Noah; Orchard, David; Walsh, Norman; Williams, Stuart (15 December 2004). "Architecture of the World Wide Web, Volume One". Version 20041215. W3C.
• Berners-Lee, Tim (August 1996). "The World Wide Web: Past, Present and Future".
• Fielding, R.; Gettys, J.; Mogul, J.; Frystyk, H.; Masinter, L.; Leach, P.; Berners-Lee, T. (June 1999). "Hypertext Transfer Protocol – HTTP/1.1". Request For Comments 2616. Information Sciences Institute.
• Niels Brügger, ed. Web History (2010) 362 pages; Historical perspective on the World Wide Web, including issues of culture, content, and preservation.
• Polo, Luciano (2003). "World Wide Web Technology Architecture: A Conceptual Analysis". New Devices.
• Skau, H.O. (March 1990). "The World Wide Web and Health Information". New Devices.

External links

• The first website
• Early archive of the first Web site
• Internet Statistics: Growth and Usage of the Web and the Internet
• Living Internet A comprehensive history of the Internet, including the World Wide Web
• Web Design and Development at Curlie
• World Wide Web Consortium (W3C)
• W3C Recommendations Reduce "World Wide Wait"
• World Wide Web Size Daily estimated size of the World Wide Web
• Antonio A. Casilli, Some Elements for a Sociology of Online Interactions
• The Erdős Webgraph Server offers weekly updated graph representation of a constantly increasing fraction of the WWW
• The 25th Anniversary of the World Wide Web is an animated video produced by USAID and TechChange which explores the role of the WWW in addressing extreme poverty

English Journal

• Human Chromosome Y and Haplogroups; introducing YDHS Database.

• Tiirikka T1, Moilanen JS.
• Clinical and translational medicine.Clin Transl Med.2015 Dec;4(1):60. doi: 10.1186/s40169-015-0060-7. Epub 2015 Jun 10.
• BACKGROUND: As the high throughput sequencing efforts generate more biological information, scientists from different disciplines are interpreting the polymorphisms that make us unique. In addition, there is an increasing trend in general public to research their own genealogy, find distant relative
• PMID 26061870

• Emergency department characteristics and capabilities in Bogotá, Colombia.

• Bustos Y1, Castro J, Wen LS, Sullivan AF, Chen DK, Camargo CA Jr.
• International journal of emergency medicine.Int J Emerg Med.2015 Dec;8(1):79. doi: 10.1186/s12245-015-0079-y. Epub 2015 Aug 8.
• BACKGROUND: Emergency departments (EDs) are a critical, yet heterogeneous, part of international emergency care. The National ED Inventories (NEDI) survey has been used in multiple countries as a standardized method to benchmark ED characteristics. We sought to describe the characteristics, resource
• PMID 26253755

• Transdisciplinary synthesis for ecosystem science, policy and management: The Australian experience.

• Lynch AJ1, Thackway R2, Specht A3, Beggs PJ4, Brisbane S5, Burns EL6, Byrne M7, Capon SJ8, Casanova MT9, Clarke PA10, Davies JM11, Dovers S12, Dwyer RG13, Ens E4, Fisher DO13, Flanigan M14, Garnier E15, Guru SM16, Kilminster K17, Locke J18, Mac Nally R19, McMahon KM20, Mitchell PJ21, Pierson JC12, Rodgers EM13, Russell-Smith J22, Udy J23, Waycott M24.
• The Science of the total environment.Sci Total Environ.2015 Nov 15;534:173-84. doi: 10.1016/j.scitotenv.2015.04.100. Epub 2015 May 6.
• Mitigating the environmental effects of global population growth, climatic change and increasing socio-ecological complexity is a daunting challenge. To tackle this requires synthesis: the integration of disparate information to generate novel insights from heterogeneous, complex situations where th
• PMID 25957785

Japanese Journal

• Optimal Policy Analysis in a New Keynesian Economy with Credit Market Search

• GRIPS Discussion Papers 16-30, 2017-02
• NAID 120005980292

• Incentivising the Social Discounting Task: A laboratory experiment

• GRIPS Discussion Papers 16-29, 2017-01
• NAID 120005952994

• Blowup and global existence of a solution to a semilinear reaction-diffusion system with the fractional Laplacian

• Mathematical Journal of Okayama University 59(1), 175-218, 2017-01
• NAID 120005898816

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リンク元	「ウェブ」
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「ウェブ」

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英

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インターネット、クモの巣、ウェッブ、ワールドワイドウェブ

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英

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