Kind of both? You've usually got a small motor connected to the lens that turns the focus ring.

A dedicated person, called a focus puller, has a remote with a wheel on the side. By turning this wheel the focus puller can remotely control the focus ring of the lens.

The remote usually allows the focus puller to set the maximum range of motion with A/B points. The system doesn't automatically execute the focus pull, but with the hard stops at the A/B points the focus puller can make sure they don't overshoot the target.