What Is a Web Server and How Does It Work?

What is a web server?

A web server has two meanings. It can be a computer that is always on and connected to the internet. It can also be the program on that computer that sends out web pages. Think of a waiter in a restaurant. You ask for a dish, and the waiter brings it from the kitchen.

Your hosting plan gives you space on such a computer for your website files.

What a web server stores

• Pages written in HTML, the language that describes how a page looks.
• Pictures, videos and style files.
• Scripts, which are small programs such as PHP code that build pages.
• Sometimes a database, an organised store of information.

What happens when you open a page

1. You type a website name into your browser.
2. Your browser asks DNS for the number address of the site. DNS is the internet's phone book.
3. The browser sends a request to that address. A request is a question: "Please send me this page."
4. The web server receives the request.

   

5. If the page is a plain file, the server sends it right away.
6. If the page is built by a script, the server runs the script. The script may ask the database for data.
7. The server sends the finished page back as a response.
8. Your browser draws the page on your screen.

All this takes a fraction of a second.

Static and dynamic pages

• Static: the same file for everyone, like a printed leaflet.
• Dynamic: built fresh for each visitor, like a shop page showing your basket.

Popular web server programs

Apache, Nginx, LiteSpeed and Microsoft IIS are common ones. On most hosting plans, the hosting company installs and looks after the program for you.

Why it matters to you

• A fast, stable server means a fast site.
• If the server is off, your site is off. That is why hosting runs servers all day.
• Many visitors at once need more power from the server.

Quick recap

• A web server stores your site and sends it to visitors.
• The browser asks, the server answers.
• Static pages are ready-made. Dynamic pages are built on request.
• Apache, Nginx, LiteSpeed and IIS are common programs.