This document discusses computer input and output devices. It defines input devices as peripherals that send data to computers by allowing users to communicate with computers. Output devices are defined as devices that send the results of data processing to users, allowing computers to communicate with users. Examples of common input devices include keyboards, mice, webcams, and microphones, while common output devices include monitors, printers, speakers, and projectors. The document provides examples of how input devices send data to computers to be processed, and how output devices receive the processed data from computers.