--- layout: post title: "The World Wide Web" subtitle: "The Web is one part of the Internet: the HTTP part" section: web --- ### Web We have seen how computers connected on the Internet communicate in different languages called **protocols**, to exchange emails, files, chat messages... One of these protocols is called **HTTP**. It's the protocol with which computers share **Webpages** between each other, like the one you're currently reading. The **Web** is the part of the Internet where Webpages are shared. You can tell you're browsing the Web if the URL starts with `http://`. ### Webpage A Webpage is a **document** written in HTML that is shared across the **Web**. You open these documents with a **Web browser**. To access a Webpage you can either: * type its **URL**, like `http://marksheet.io/web.html` * click on a **link**, like [this one](http://marksheet.io/internet.html) Because remembering URLs is cumbersome, the Web at its origin is based upon **interlinked documents** to make easy for users to _browse_ the Web. ### Website A **Website** is simply a _collection_ of Webpages located on a **same domain**. * **Web** `http://` * Website `marksheet.io` * Webpage `/introduction.html` * Webpage `/internet.html` * Webpage `/web.html` ### Opening a Webpage in your browser By navigating to , you're asking a computer on the Internet to get the `web.html` document. In that case, your computer is the **client**. You're asking the MarkSheet **server** (on which the website is hosted) to get the file called `web.html`.
Client Your computer Hi MarkSheet computer! I'd like the web.html file please
Server The MarkSheet computer Let me check if it's there...
Client Your computer Ok I'll wait
Server The MarkSheet computer Oh, here it is! Let me send that to you.
Client Your computer Got it. Thanks!
Your browser is then able to display `web.html`. The file is **not saved** on your computer though: it is only displayed temporarily while you navigate it. If you go to later, it will ask the MarkSheet computer _again_ for that same file, if it still exists. That way, it ensures you always get the _latest_ version of the file. Web : The part of the Internet that uses the **HTTP** protocol. Webpage : A document written in **HTML**. Website : A collection of Webpages on the same **domain**. Browser : A program that can **open** Webpages in order to display them. *[HTTP]: HyperText Transfer Protocol