All lenses are made for specific mounts. This is how the lens fits on the camera body both physically and electronically. The contact points communicate information from the lens to the camera and vice versa. The lenses attach to the camera using a lens mount, which often also contains mechanical or electrical linkages between the lens and camera body. The lens mount is an important issue for compatibility between cameras and lenses; each major camera manufacturer typically has their own lens mount which is incompatible with others. Most large-format cameras take interchangeable lenses as well, which are usually mounted in a lens board or on the front standard.