A mainframe or mainframe computer is a large powerful computer which can be used by many people at the same time and which can do very large or complicated tasks.
英英词典释义
Noun
1. a large digital computer serving 100-400 users and occupying a special air-conditioned room
2. (computer science) the part of a computer (a microprocessor chip) that does most of the data processing; the CPU and the memory form the central part of a computer to which the peripherals are attached