How the Web Works?

Surfing the web is easy as pie. Let’s say you want to read today’s comic from the popular website xkcd. You type the text $"xkcd.com"$ in your browser’s address bar and voila, the comic appears (assuming no network issues).

Let’s try to understand what’s going on behind the scene.

Web servers

To view a website online, it has to be published on a server. A server is a special kind of machine whose task is to listen and answer to the demands of clients. A server that publishes resources on the Web is logically called a web server.

More precisely, a web server machine runs a particular software program (also called a web server) able to publish websites. The most popular ones are Apache , Microsoft IIS, and nginx.

Web clients

The machine asking a server for a resource is called a web client. Actually, the real client is a software program running on the machine. A well-known type of web client is the browser, a program specialized in displaying web pages. Famous web browsers include Mozilla Firefox, Chrome, Safari, and Opera.

Not all web clients are browsers, through. For example, search engines robots and mobile applications also contact servers and ask them for content.

Communications between clients and servers