Cameras work on the same basic principles. Cameras are made up of a light-proof box with film inside and a lens at the front. There is an adjustable hole, or aperture, where light enters the box and is focused. The lens most of the time is glass, but it can also be plastic or any transparent disk. A lens refracts, or bends light.
Light passes through the lens, and the light is bent to a common point, or focus.
A lens also has a set focal length, where the light will always come to the same focusing point. When you open the shutter by pushing a button on top of the camera, light goes through the lens and hits the film. When you have your film developed, the latent image on the film is brought out and made into pictures. The digital camera works the same way as a film camera, except when light enters the lens, instead of imprinting on film, the image is collected as tiny dots of light and color called pixels. Pixels are recorded on a computer chip called a charge couple device.