What kinds of computer servers are there available?

There are 3 different types of computers in common use; * PC(Personal Computer) - These are the standard desktop or tower computers. They have standard operat5ing systems on them and are used for general personal and/or business use. * Laptop - Also known as Notebooks. These are portable computers. They are more compact than PC's as well as more durable...and usually more expensive. Uses are similar to PCs. * Servers - Physically these may resemble PCs, or may come on a rack-mountable form. The operating systems on these are designed to provide services, such as email, websites, FTP and the like. They are more basic as far as convenience applications go, but are more robust.