Basically it is the full camera support device, while a jib is the arm that projects from the camera crane where the camera mounts, allowing a camera operator to control the booming, swinging, tilting and panning of the camera.

In cinematography, a jib is any boom device used to mount a camera on one end, and a counterweight with camera controls on the other. In principle, it operates like a see-saw, with the balance point located closer to the counterweight, which allows the end of the arm with the camera to move through an extended arc.

The jib allows for added maneuverability, which is in addition to the up and down hoisting action of a crane. This greater range of motion that a jib provides is extremely useful in stone fabrication operations. While a crane can be used without a jig, you must have a crane or other attachment to use a jig.