This document discusses various types of input devices that can be used to enter data and instructions into a computer. It begins by defining key terminology related to input, including programs, commands, and user responses. It then provides details on commonly used input devices like keyboards, mice, touchscreens, microphones, and scanners. It describes the components and features of desktop and mobile keyboards. The document discusses ethics around privacy issues with keyboard monitoring software. Overall, the document provides an overview of different input devices and how users can interact with computers.