How does a camera work?

A camera works much like the human eye. Light from a scene passes through a lens, which focuses it to form a sharp image. In a digital camera, that light lands on an electronic sensor made of millions of tiny light-detecting pixels, which measure the brightness and colour at each point and store it as a digital image. The amount of light is controlled by the aperture size and the shutter, which sets how long the sensor is exposed. Older cameras recorded the same focused light onto chemical film.