iSight is a brand name used by Apple Inc. to refer to cameras on various devices. The name was originally used for the external iSight webcam, which retailed for US$149, connected to a computer via a FireWire cable, and came with a set of mounts to place it atop any then current Apple display, laptop computer, all-in-one desktop computer, or flat surface.
Apple iSight webcam
Apple iSight webcam
A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in video telephony, live streaming and social media, and security. Webcams can be built-in computer hardware or peripheral devices, and are commonly connected to a device using USB or wireless protocols.
A Logitech-branded webcam attached to a laptop.
SGI IndyCam
iSight webcam, released in 2003
Charge-coupled device (CCD) image sensor of a webcam