This document provides an overview of computers and their components. It defines a computer as an electronic machine made up of hardware and software. The main components are the central processing unit (CPU), memory, storage, input devices, and output devices. Common input devices include keyboards, mice, and scanners, while common output devices include monitors, printers, and speakers. Memory is either primary memory (RAM) or secondary storage like hard disks. Factors that influence computer performance include CPU speed, memory capacity, hard disk speed, and bus speed.