This is an old revision of the document!
Hardware Servers can vary widely from personal computers to specially built rack mounted computers and depends on the amount of work that needs to be done and the number of clients that need to be supported. For example, quite often database servers are software that can run on a person computer to service the needs of an individual using the machine as a personal computer or can be on many rack mounted servers supporting thousands to millions of clients. As a general rule, Servers are more often than not, more powerful and expensive than the clients that connect to them.
Since servers are usually accessed over a network, many run unattended without a computer monitor or input device, audio hardware and USB interfaces. Many servers do not have a graphical user interface (GUI). They are configured and managed remotely. Remote management can be conducted via various methods including Microsoft Management Console (MMC), PowerShell, SSH and browser-based out-of-band management systems such as Dell's iDRAC or HP's iLo.