What is a web server and which is the best?

The term 'web server' can mean two things - a computer/machine that hosts web sites (hardware) and a software that runs on such a machine and processes requests from browsers (also called client software). Generally, the context will make it very clear if the term "web server" is being used for the machine or the software.

In this article I shall provide some information on web server software. If you want details on web server machine, I suggest you read "how is a web hosting Server different from your home/office machine?"

What is web server software?

A web server is special software capable of servicing HTTP (Hypertext Transfer Protocol) requests. For this reason, web server software is also referred to as HTTP server.

OK... in English.

A web server is a program (software) helps serve web pages to browsers. FYI, this software is responsible for sending not only the actual web page file to the browser but also any embedded documents such as images, video, audio etc. The web server runs the HyperText Transfer Protocol which is a set of rules for two computers to talk to each other.
[And that was my best attempt at putting it in the simplest language possible].

So when you open a web site in your browser (called the client software), a request is sent to the web server on a remote machine. This web server software processes your browser's request and tries to locate the web page. If it finds it, the web server sends the web page to your browser which then displays it. In case when the web document cannot be located, the server software lets the browser know of that too!

Popular web servers

According to Netcraft web server usage survey, Apache HTTP server is the most popular web server with a large market share of almost 60%. The popularity of Apache is followed by Microsoft's web server. The share of other web servers is very small compared to these two. Refer the Netcraft web server survey for further details.
List of web servers.

Can you run a web server on your computer?

Oh yes! For example, I run the Apache web server on my Windows XP computer. I do this to test the scripts I write (in PHP and Perl) for web sites before I put them online. I find this process easier and quicker than trying to work off a remote server. So if you are planning to develop a web site that runs PHP or Perl scripts, I would definitely recommend that you get a copy of the Apache web server; learn how to install Apache on Windows 7 computer.

Finally, to know which server your site is running on check it with Netcraft's What's that site running on? Tool.