The lens body is the tubular outer casing which houses the optical lenses (glass lens elements) and mechanisms for controlling the lens movement and aperture. A lens body can be either:
• Built into the camera permanently.
• Be the casing/mount for an interchangeable photographic lens.
Interchangeable lens bodies allow different photographic lenses to be fitted to a single camera body. The lens body, including the mount, is built for one type of camera. The mount determines which camera a lens will fit. Different lens mounts cannot be changed on a lens body.
Before buying an interchangeable lens of any sort check it’s mount and general compatibility with the camera you are going to use.