What Is A Camera?
A camera is an optical instrument used for recording images. The images may be individual still photographs or a collection of images used for videos and movies. The word camera comes from camera obscura, which means "dark chamber." The functioning camera is very similar to the functioning human eye.
How A Camera Works
A camera is a lightproof box containing light-sensitive film. To take a picture, the photographer presses a button to open the shutter that lets light through the aperture which is a hole in the front of the camera. The camera lens focuses on the the light so that it forms a sharp image on the photographic film just as the lenses in our eyes focus the light onto our retinas.Then the shutter closes again so that no more light gets in. This whole process takes barely a second.