Meaning – The term mainframe, refers to a computer, usually in a computer center, with extensive capabilities and resources to which other computers may be connected so that they can share facilities. Originally referred to the central processing unit of a large computer, which occupied the largest or central frame (rack).

A mainframe computer is larger and has more processing power than some other classes of computers, such as minicomputers, servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers.

Example of usage “Mainframes have high availability, one of the primary reasons for their longevity, since they are typically used in applications where downtime would be costly or catastrophic. The term reliability, availability, and serviceability (RAS) is a defining characteristic of mainframe computers. Proper planning and implementation are required to realize these features.”