A mirror is a surface that allows light to bounce off of it almost perfectly. (It will also bounce heat and sound, too). Mirrors are often flat, but they may also be curved, such as in the car wing mirror shown above, or the mirror behind a torch/flashlight bulb.

When you look at something in a mirror, it is always changed in some way. For example if you look at yourself in a mirror, you see yourself the other way around (left to right) to the way other people see you. In curved mirrors your shape may be upside down, squashed in or pulled out.

Mirrors are often made with a sheet of transparent material, such as glass or plastic, combined with a thin film of silver spread over the back. The glass or plastic supports the silver, and also protects it from scratches and tarnishing.