Microcomputers or Personal Computers – Personal computers come in two major varieties, desktop computers and laptop computers:
–Desktop computers – They are larger and not portable. Normally they are big enough to sit on a table. A case contains all computer’s main parts and keyboard-mouse are separate to operate. A LCD or CRT display is there so we can view output.
–Laptop or notebook computers – They are small and light weight and come in a box. A built in LCD is connected to laptop and keyboard and touch pad are on other part of it. Laptop cost more than desktop if we buy at same configuration.
PDAs and Palmtop Computers:
–Personal Digital Assistant (PDA) – is a handheld microcomputer that trades off power for small size and greater portability. They typically use a touch-sensitive LCD screen for both output and input (the user draws characters and presses icons on the screen with a stylus).
–Palmtop or handheld PC- is a very small microcomputer that also sacrifices power for small size and portability. These devices typically look more like a tiny laptop than a PDA, with a flip-up screen and small keyboard.
Workstations/Servers- is a powerful, high-end microcomputer. They contain one or more microprocessor CPUs. They may be used by a single-user for applications requiring more power than a typical PC (rendering complex graphics, or performing intensive scientific calculations).
Minicomputers – is a multi-user computer that is less powerful than a mainframe. This class of computers became available in the 1960’s when large scale integrated circuits made it possible to build a computer much cheaper than the then existing mainframes (minicomputers cost around $100,000 instead of the $1,000,000 cost of a mainframe).
Mainframes – A mainframe computer is a large, powerful computer that handles the processing for many users simultaneously (up to several hundred users).
Supercomputers – A supercomputer is mainframe computer that has been optimized for speed and processing power. The most famous series of supercomputers were designed by the company founded and named after Seymour Cray.