A server is a large computer with a lot of computing power. It provides services to client computers, like your desktop at home. This video delves into the particulars of what a server is and how it works.
Servers can be used for a variety of functions. Web servers host websites. Database servers give clients access to a host of information. Email servers are used to provide electronic mail services.
A server may be dedicated to a single operation. Larger corporations are more able to do this. Smaller organizations usually rely on a single server running multiple operations, including data, web, and email hosting.
A server is not a specific type of computer, but a role that a particular computer fills. A desktop computer can even be set up as a server. You can set up a network in your home to work as a file server that other computers can access. You can also use a desktop as a web server. However, desktop computers do have limitations. They cannot handle large data and a lot of network connections due to their hardware and software.
For more information on servers and the functions they can provide, check out the video in the link above.