A webcam is a video camera that feeds or streams its image in real time to or through a computer to a computer network.
When "captured" by the computer, the video stream may be saved, viewed or sent on to other networks via systems such as the internet, and emailed as an attachment.
For a more complete list see Comparison of webcam software.
Special software can use the video stream from a webcam to assist or enhance a user's control of applications and games.
With very-low-light capability, a few specific models of webcams are very popular to photograph the night sky by astronomers and astro photographers.
Mostly, these are manual-focus cameras and contain an old CCD array instead of comparatively newer CMOS array.
This can be applied to games, providing additional control, improved interactivity and immersiveness.
Free Track is a free webcam motion-tracking application for Microsoft Windows that can track a special head-mounted model in up to six degrees of freedom and output data to mouse, keyboard, joystick and Free Track-supported games.
The Eye Toy for the Play Station 2, Play Station Eye for the Play Station 3, and the Xbox Live Vision camera and Kinect motion sensor for the Xbox 360 and are color digital cameras that have been used as control input devices by some games.
Small webcam-based PC games are available as either standalone executables or inside web browser windows using Adobe Flash.
Webcams have been used for augmented reality experiences online.