Use the built-in camera on Mac
Many Mac computers and displays have a built-in iSight, FaceTime or FaceTime HD camera located near the top edge of the screen. The camera automatically turns on when you open an app that can take pictures, record videos or make video calls. You can decide which apps are allowed to use the camera on your Mac. See Control access to your camera on Mac.
Turn the camera on: On your Mac, open an app that can use the camera, such as FaceTime, Messages or Photo Booth. A green light beside the camera glows to indicate that the camera is on.
Turn the camera off: On your Mac, close or quit all apps that can use the camera. The green light beside the camera turns off, showing that the camera is off.