Although this classification of computers was fairly rigorous till about 10 years ago, the rapid advance in technology has blurred the distinctions between these categories. For example, the technical definition of a microcomputer is a computer that uses a microprocessor for its main processing activities. But now-a-days, even mainframes and supercomputers use a collection of standard microprocessors. A computer at the higher end of the microcomputer range may possess the power of a minicomputer, and support more than one user at a time, but cost less. Soon we may have microcomputers which may outperform the mainframe of today. A mainframe may have the same processing power of a lower end supercomputer.