A manual pallet jack is a hand-powered jack

A manual pallet jack is a hand powered jack. Most commonly seen in retail and personal warehousing operations.
Powered pallet jacks, also known as electric pallet trucks, walkies, single or double pallet jacks, or power jack, are motorized to allow lifting and moving of heavier and stacked pallets. Some contain a platform for the user to stand while moving pallets. The powered pallet jack is generally moved by a throttle on the handle to move forward or in reverse and steered by swinging the handle in the intended direction. Some contain a type of dead man's switch rather than a brake to stop the machine should the user need to stop quickly or leave the machine while it is in use. Others use a system known as "plugging" where in the driver turns the throttle from forward to reverse (or vice versa) to slow and stop the machine, as the dead man's switch is used in emergencies only.