This document provides an introduction to computers and their components. It defines a computer as a machine that can carry out arithmetic and logical operations automatically according to programming instructions. It then lists and describes the major internal and external components of a computer, including the central processing unit (CPU), motherboard, memory (RAM), hard drive, graphics processing unit (GPU), power supply, input/output devices, and optical drives. It also discusses computer data representation systems such as binary, octal, decimal, and hexadecimal numbering.