A webcam is a small camera peripheral that captures video and still images for a computer, used for video calls, streaming, and recording.1
Overview
A webcam pairs an image sensor and a lens with a small processor that encodes the picture into a video stream the computer can read. It is an input device: the operating system sees it as a camera source that applications tap into. The specs that matter are resolution (1080p and 4K are common), frame rate (frames per second), and field of view (how wide a scene it captures). Webcams connect over USB or come built into a laptop bezel or a monitor.
Where it fits
The webcam became a fixture of remote work and online classes, and a step up from a built-in camera noticeably improves call quality. Beyond conferencing, the same hardware feeds streaming, security monitoring, and computer-vision projects. As a plain USB video source it slots neatly into homebrew automation — much as a software-defined radio is a USB input feeding a stream into the computer, a webcam feeds a frame stream that software can capture and process.