explain the workig of a camera

Working of a camera:

Light travels through the lens to the back of the camera where it reaches a mirror that sits between the lens and the film. When the light hits the mirror it changes direction, up towards a prism in which it changes direction a couple of times again so that it ends up going through the viewfinder window. The user can then see what will appear in the photograph that they are taking. Pressing on the shutter release button opens the shutters or sliding doors allowing light to enter the camera. At the same time, the mirror is moved out of the way so light hits the film instead. A chemical reaction happens to the film in those moments, capturing an image of what the user has seen through the viewfinder. With many cameras the user can control how much light is let in by adjusting the speed the shutter opens at, the aperture (how wide the shutter opens) and the lens focus. Many cameras have a flash fitted, in case there is not enough natural light for the process to work.