Light is a name for a wide scale of electromagnetic radiation that can be seen by the human eye. Electromagnetic radiation has a dual nature as both waves and particles. In terms of the recent quantum theory, electromagnetic radiation consists of particles called photons, which are packets of energy which travel at the speed of light.
when you look through the lens before taking the picture the image is actually being 'bounced' off several mirrors.
when you take the photo the mirrors fold back and are captured in the camera.
when you are finished taking the photo they go back intoplace so you can see through it again.
Every camera is essentially a lightproof box, with some method of letting in just a small amount of light at just the right time. Once the light is in the box, it forms an image, like in the camera obscura, causes a chemical reaction on photographic film, or energizes a photocell, like in a digital camera.
