A computer case (also known as a "computer chassis", "cabinet", "box", "enclosure", "housing", or simply "case") is the enclosure that contains most of the components of a computer (usually excluding the display, keyboard and mouse).
Cases are usually constructed from steel (often SECC — Steel, electrogalvanized, cold-rolled, coil) or aluminium.
Types of Computer Cases:
Tower Case (Full, Midi and Mini)
These cases usually sport up to multiple drive bays, and as a result, are the most expensive computer cases in the market. There is actually a middle-ground tower, called the midi, which can host 4-5 drive bays, but some manufacturers don’t usually separate the two types. Tower cases are differentiated by the number of drive bays that they support. Mini towers have three drive bays, though the number may be different, depending on the company or store that you buy your case from.
This type of case in which the monitor sits on top of the case has the fewest alternative available on the market. But even with proliferation of Tower Cases, some computers are still based on this type.
This type of case is usually the lightest and the most portable in the market. Commonly use by Notebooks, Laptops, Tablet PC Case, and PDA’s (Personal Digital Assistant) such as a palm pilot and blackberry.
This type of case is very popular with Apple computers, it is slim and cool looking, and the only drawback of course is if some component breaks inside your kind out of luck. These days personal computers are also coming in such casings,
An tower case -