How Does the World Wide Web Work?

The World Wide Web is built on a small set of clear ideas. This article covers them twice: a one-line plain-language summary first, then a fuller breakdown of what each piece actually does.

For the history of the Web (Tim Berners-Lee, CERN, 1989, Mosaic), see WWW History. For the basic definition and examples, see What is WWW?.

The Five Core Technologies, in Plain Language

A quick, one-line description of each:

1. HTTP, the rules that move pages from servers to your browser.
2. HTML, the language that builds web pages.
3. URLs, the addresses of pages (for example, https://wikipedia.org).
4. Web browsers like Chrome, Firefox, and Safari that display the pages.
5. Web servers that store the pages and send them when a browser asks for them.

That is the whole picture in five lines. The next section explains each piece in a little more detail.

How Does the WWW Work?

The WWW works through five core technologies. Each one has a clear job.

1. Web Browsers Web browsers, such as Chrome, Firefox, and Safari, let users visit and use websites. A browser is the interface between the user and the World Wide Web.

2. Hypertext Transfer Protocol (HTTP) HTTP is the protocol used to move data between web servers and browsers. It makes sure webpages load correctly on a user’s device.

3. URLs (Uniform Resource Locators) Every webpage has a unique URL, which is its address on the web. Common examples are https://www.google.com, https://www.wikipedia.org, and https://www.youtube.com.

4. HTML (Hypertext Markup Language) Webpages are built using HTML. HTML controls how content looks on screen, including text, images, links, and multimedia.

5. Web Servers Web servers store website data. When a browser requests a page, the server sends the content back to the user.

Flashcard

What are the 5 core technologies that make the WWW work?

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Answer

Web Browsers, HTTP, URLs, HTML, and Web Servers

• Browsers display pages
• HTTP moves data
• URLs are page addresses
• HTML builds page content
• Web Servers store and send data

Flashcard

Break down the URL https://www.wikipedia.org into its parts.

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Answer

Three parts:

1. https:// — the protocol (the secure version of HTTP).
2. www. — the subdomain that points to the web service of this site.
3. wikipedia.org — the domain name, which identifies the site itself.

A browser uses the URL to find the right web server and ask it for the page.