What is a server?

I have been hearing and reading about servers for some time but have not had a reason to know anything about them. Please explain what they are and what they do and why does anyone want or need one.

Thanks!!

 

Most people see a server as a machine that hosts some information that is accessable to many users over a network.

Example:

majorgeeks.com is being hosted by a server. This server accepts requests from users ie. you and me to view the webpage.
All the webpages are held on the server computer and when you type http://www.majorgeeks.com into your web browser the browser will send out a request for a file. By default this file is usually index.html. This file is then sent back to the user where it is shown as a webpage.

Alot of people mix up the fact that a server is hardware but it is not. A server is simply a program that is running on a machine that accepts user requests for files on certain ports.

As an example i can very easily turn my laptop into a webserver by running a server application that i wrote in java. On execution of this program a certain port that i specify will get binded to the server application. This application will then listen(ie. wait) for someone to try and connect to that port. When someone connects a certain set of commands is sent to the server by the person connecting to the server(your webbrowser does this automatically). These commands tell the server what file it has to return to the user.


Summary & Simplification

A server is a program that handles requests from users for files that are located on the same machine as the server.

Im sorry but im not the best at explaining things. maybe someone else can clarify what have said.

 

Thank you, Sagem. I am considerably more enlightened at this time. Your explanation was quite clear.