When working in a business environment, you may well hear people tell you that something is stored "on the server". This jargon buster will let you know exactly what is being referred to here.
Somewhat confusingly, a server has two meanings - one hardware and one software. However, these usually go hand in hand so that hardware servers run software servers.
When referring to hardware, a server is just a computer that has been tasked with running one or more software servers. Therefore, as you can see, the term "server" can be very broad.
Some real world examples should help clarify things. For example, we run a web and email hosting server for many of our clients. This server runs a web server (so that the web pages load), an email server (to process all the email), an FTP server (so people can access the files on their website), and few other types of software servers relating to websites.
Equally, business customers frequently have a file server that everyone can access to share files. This is usually a real computer sitting in the office somewhere that is running software to allow this file sharing to work. However, these days, this may also be a "cloud" server. Although this sounds complicated, the only difference here really is that the computer with the files on is just somewhere else.
One thing that does differentiate hardware servers from the devices that you use is that they often run different operating systems than those you might use. Microsoft have special "Server" versions of their operating systems. While these appear similar to Windows, they have many additional functions, as well as many features of standard Windows removed. Linux is also very popular in the server world, as it enables you to configure a server to do exactly what is required of it and nothing more to keep things speedy and reduce the chance of the server being compromised via unneccessary features.