World Wide Web

The World Wide Web (also known as WWW, W3, or simply the Web) is a public system for sharing information over the Internet. It lets people access documents and other web resources using the Hypertext Transfer Protocol (HTTP).

The Web was invented by English computer scientist Tim Berners-Lee while at CERN in 1989 and opened to the public in 1993. It was designed as a "universal linked information system." Documents and media are available through web servers and can be viewed using programs called web browsers. Servers and resources on the Web are identified by a special string called a uniform resource locator (URL).

A web page from Wikipedia displayed in Google Chrome

The most common type of document on the Web is a web page written in Hypertext Markup Language (HTML). HTML supports plain text, images, embedded video and audio, and scripts that allow interactive features. It also includes hyperlinks, which let users jump quickly to other web resources. The practice of moving from one webpage to another by clicking these links is called web navigation or web surfing.

Today, the World Wide Web is the main way billions of people around the globe use the Internet. It provides a vast range of educational, entertainment, commercial, and government information from companies, organizations, agencies, and individual users.

History

Main article: History of the World Wide Web

This NeXT Computer was used by Sir Tim Berners-Lee at CERN and became the world's first Web server.

The World Wide Web was invented by English computer scientist Tim Berners-Lee while working at CERN. He made it to help people store and share documents and data more easily in big groups. His idea used a special way to connect documents with links, which made finding information much simpler.

The Web became available to everyone in 1993. It grew fast as more people used it to share information online. Browsers like Mosaic and Navigator made it easier to see pictures and fill out forms, helping the Web become popular. Today, the World Wide Web is a big part of how billions of people use the Internet.

Nomenclature

Tim Berners-Lee says that "World Wide Web" should be written with three separate words, each starting with a capital letter, and no hyphens between them. The "www" prefix is used less often now. Popular services like Gmail.com, Outlook.com, Myspace.com, Facebook.com, and Twitter.com are usually mentioned without "www." or even ".com."

In English, people usually say "www" as "double-u double-u double-u." Some say it as "dub-dub-dub," especially in New Zealand. Writer Douglas Adams once joked that the short form of the World Wide Web takes longer to say than the full name.

Function

Main articles: HTTP and HTML

The Internet and World Wide Web are often used as if they are the same thing. But they are not. The Internet is a big system of computer networks connected through wires and optical networking. The World Wide Web is a collection of documents and other resources, linked together by hyperlinks and URIs. We use HTTP or HTTPS to get these web resources. These are special ways to send and receive information over the Internet.

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

To see a web page on the World Wide Web, you usually type the URL of the page into a web browser, or click on a hyperlink. The web browser then works behind the scenes to get and show the page you asked for. In the 1990s, people started calling this action 'browsing,' 'web surfing' (like channel surfing), or 'navigating the Web'.

Hypertext Markup Language (HTML) is the main markup language for making web pages and web applications. With Cascading Style Sheets (CSS) and JavaScript, it is one of the key tools for the World Wide Web.

Most web pages have links to other pages, files, or resources. These links connect many useful pieces of information, creating a web of data. Tim Berners-Lee first used the name WorldWideWeb in November 1990.

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

A web page is a document made for the World Wide Web and web browsers. A web browser shows a web page on a monitor or mobile device.

A website is a group of related web resources, such as web pages and multimedia content, usually found under one domain name, and stored on a web server. Examples include wikipedia.org, google.com, and amazon.com.

A web browser is a program that lets you see information on the World Wide Web. You need a web browser to connect to a website and see its pages.

A Web server is special server software or hardware that runs this software. It can handle requests from people wanting to see websites. A web server can hold one or more websites. It processes requests using HTTP and other similar ways to communicate.

Security

The Web can be a place where bad people try to do harmful things. They might try to steal personal information or trick people for money. Some of these problems can happen on real websites.

Big security companies make tools to help keep data safe. Some experts think everyone should help keep the Internet secure.

Privacy

Main article: Internet privacy

When you visit a website, the server can see your computer's unique address, called an IP address. Most websites keep records of who visits and what pages are viewed.

Sometimes, websites ask for your name, address, or email. They might remember your visits and learn about your interests. This information can be used by companies for advertising. Social networking sites often ask for real names and locations. It's important to think carefully about what you share online.

Standards

Main article: Web standards

Web standards are important rules that help websites work together and be easy for everyone to use. These rules are made by groups like the World Wide Web Consortium and the Internet Engineering Task Force. They make sure websites are safe, easy to use, and work well for everyone.

These rules change as new technologies appear, so the web stays useful and open for all.

Accessibility

Main article: Web accessibility

The Web can be used by people with different kinds of disabilities, such as trouble seeing, hearing, or moving. Special features help make the Web easier for everyone, including those with temporary injuries or older users. The World Wide Web Consortium thinks it's important for the Web to be accessible so that all people can use it equally. Many countries have rules that websites must follow to include these features. Guidelines from the W3C's Web Accessibility Initiative help website makers and software creators make the Web usable for everyone.

Internationalisation

The W3C Internationalisation Activity helps make sure that web technology works with all languages and cultures. Around 2004 or 2005, Unicode started being used more on the web. By December 2007, it was used more often than older systems like ASCII. New rules now let web addresses include letters from any language in the world.