A server is a
on a network that provides services to clients using other computers on the same network.
A file server is a computer on a network that has files that people can have access to.
A printer server is a computer on a local network that has a printer attached to it so that the printer can be shared by several users.
A web server is a computer with special software that is used to distribute webpages over the world wide web. Every web server has an IP address and perhaps a domain name.
Simple Client-Server Architecture
The client might be you using your computer to obtain information from the web server, that contains the information that you need, using the internet. When you type a url in your browser such as www.google.com, your browser sends a request to the server on the internet. The server looks at the request and see if it is a valid request that can be fulfilled. If there are no errors and the server is running, it will send a respone in the form of a webpage. This is called a simple request-response model. (see figure 1 below)
Figure 1 - Client-Server Model
Two types of content in web servers:
1 - Static content : server sends an existing file
2 - Dynamic content : content may be generated on the fly by programs running on the server or/and on the client computer.
Books and References
1 - Web Server Technology 1st Edition - Nancy J. Yeager, Robert E. McGrath - ISBN-13: 978-1558603769
2 - Computer Networking: A Top-Down Approach (6th Edition) 6th Edition - James F. Kurose and Keith W. Ross - ISBN-10: 0132856204
3 - Computer Networks (5th Edition) 5th Edition - Andrew S. Tanenbaum and David J. Wetherall - ISBN-10: 0132126958