The document provides an introduction to understanding the computer system. It discusses the major hardware components of a computer system including the system unit, motherboard, CPU, primary storage, expansion bus, adapters, power supply unit, hard disk drive, optical drive, and digital versatile disc. It also discusses input devices like the keyboard and pointing devices, output devices like the computer display monitor and printer, ports, cables, and wires. It defines software and describes the two main types: system software and application software. The objectives and skills test assess understanding of computer hardware servicing.