workstation. Large insurance companies and banks would use the mainframe to keep track of their policy holders and accountholders. The most powerful computers in terms performance and data processing are the supercomputers. These are the fastest computers with large data storage capacity. Supercomputers are very expensive and very large in size. It can be accommodated in large air-conditioned rooms; some pcs can even occupy an entire building. Supercomputers are specialized and task specific computers used by large organizations. These computers are used for research and space explorations, nuclear research purpose; likewise NASA uses supercomputers for launching space shuttles, controlling them and for space exploration purpose. Some other uses are weather forecasting, earthquake studies and nuclear weapons testing.