What is Mainframe?

[Amol21]

Hi,
What is mainframe?
My friends were talking about this last morning & i just dont know what is this?
Anyone to guide me?

[Olga]

Mainframe is a High performance Multi User computer system which is the most scalable, available, reliable and secured machine in the world capable of performing some Million Instructions per second (upto 569,632 MIPS).
A mainframe is simply a very large computer. And totally different from what you have on your desk.

[Natalie]

A computer used to control large databases, perform high volume transaction processing, and generate reports from large databases.

Mainframe is an industry term for a large computer. The name comes from the way the machine is build up: all units (processing, communication etc.) were hung into a frame. Thus the maincomputer is build into a frame, therefore: Mainframe

[deoWo]

A very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe. The distinction between small mainframes and minicomputers is vague, depending really on how the manufacturer wants to market its machines.

[Amol21]

Thanks a lot for for your replies guys!
I got to understand the basics of what this Mainframe actually is!
I appreciate you all!