What is the Web?

The Web is a collection of documents and applications connected with links and reached through URLs.

The Internet is the network underneath it. It connects computers around the world. The Web is one of the things we use that network for, just like email is another.

When you visit a website, two programs take part in the exchange:

• a browser, such as Chrome, Firefox, or Safari
• a server, a program that waits for requests and sends back responses

The browser asks for a resource. The server responds with that resource. Very often the response contains HTML.

browser  -- request -->  server
browser  <-- response -- server

HTML describes the content and structure of a page. CSS controls its presentation. JavaScript can add behavior.

Those three technologies work together, but HTML comes first. A page can work without CSS or JavaScript. Without HTML, there is no document for the browser to show.

In this course we’ll focus on the document. You will learn what each part means and how to choose elements that describe your content clearly.

Try it

Open any page, right-click, and choose View Page Source. What you see is the HTML response the browser received. It may look busy. That’s fine. By the end of this course, its structure will make much more sense.