There are different types of this kind of conveyor. There are gravity ones that do not need electricity but depend on the placement of the conveyance to automatically allow the boxes or pallets to roll down to their destination. This saves the company a lot of money on energy bills. The powered ones use a belt, chain or other mechanism together with an electric motor.
There are incline conveyors which elevator conveyor move loads up and down and bucket conveyors which carry materials in a bucket. You also have screw conveyors which move loads turning a screw-type mechanism, belt conveyors which move using a belt and chain conveyors which move items using a chain. All of which do an excellent job and save hours of manpower which would otherwise be needed to complete the same job.