Question

How do point and shoot cameras differ from SLR cameras?

Answer 1

There are two types of consumer film cameras on the market -- SLR cameras and "point-and-shoot" cameras. The main difference is how the photographer sees the scene. In a point-and-shoot camera, the viewfinder is a simple window through the body of the camera. You don't see the real image formed by the camera lens, but you get a rough idea of what is in view.
In an SLR camera, you see the actual real image that the film will see. If you take the lens off of an SLR camera and look inside, you'll see how this works. The camera has a slanted mirror positioned between the shutter and the lens, with a piece of translucent glass and a prism positioned above it. This configuration works like a periscope -- the real image bounces off the lower mirror on to the translucent glass, which serves as a projection screen. this is where i found the information( http://electronics.howstuffworks.com/camera5.htm)