Mainframes are more powerful than minis. They operate at very high speeds, have very large storage capacities and can support hundreds of users.
They are used for data processing in large organizations where the records of thousands of employees have to be processed. They are also used to manage large centralized databases. Such databases are normally queried by hundreds of users who need to access information from different locations. They are used as controlling nodes in Wide Area Networks (WANs).
Examples of mainframes are: IBM 3000 series, Burroughs B 7900 and Univac 1180.
IBM Mainframe