The computer now is offer many variety of system for users choose. Computer system are generally in one of four categories: small, or micro computer, medium size or midrange computer, large or mainframe computer and super powerful supercomputers. In practice, classifying a computer into one of these five categories by size alone is not always completely accurate. Large midrange computer, for example, often are bigger than small mainframes. In addition, the types of computers that fit into each category are continually changing as technology changes, so these categories can't be defined precisely and instead used as general guidelines. As a rule of thumb, larger computer have greater processing power. For example, big computers usually process data faster than small computer. Big computer can also accomodate larger and more powerful peripheral devices. Naturally, more powerful computers and peripherals equipment have bigger price. A computer system can cost anywhere a few hundred d...