The camera body is the most basic part of a camera. It is the box that holds the film and the camera controls. The lens is either built-into the body or attaches to the body. The body also houses a battery that powers the shutter, flash, light meter, and other controls. There are generally rings to connect a strap to the camera for easy carrying as well.
The lens is the part of the camera (or an attachment for the camera) that focuses light into the body and onto the film. The aperture is also contained within the lens.