What is the meaning of Mainframe?

A large, powerful computer able to manage very many simultaneous tasks and communicate with very many connected terminals; used by large, complex organizations (such as banks and supermarkets) where continuously sustained operation is vital.

A computer chassis that hosts and interconnects modules that perform various tasks.

The main frame of a vehicle etc., more commonly main frame.

mainframe (large, powerful computer connected to terminals)

mainframe (large, powerful computer connected to terminals)

mainframe (large, powerful computer connected to terminals)

mainframe (large, powerful computer connected to terminals)

Source: wiktionary.org