Hardware consists of equipment in five categories: input, output, processing, and memory, secondary storage, and communications.
Input is by means of keyboard, pointing (mouse, trackball, joystick, scanning (fax machine, image scanner), and voice-recognition devices.
Output is by screen (CRT, flat panel display), printer (dot matrix, laser, ink-jet), and sound.
Processing and memory hardware consists of the CPU 9 the processor) and memory. Secondary storage stores data on floppy-disk, hard disk, optical disk, and magnetic tape devices. Communication devices include modems (for enabling computers to talk over the phone lines), cable, and fax modems.
Hardware us what most people think of when they picture computers. Hardware consists of all machinery and equipment.