A Pallet Jack is a tool used to lift and move pallets from one place to another. They are also know as a pallet truck or pump truck. Apposed to a Powered Pallet Jack where they are motorized to allow lifting and moving of heavier and stacked pallets, a Manual Pallet Jack is a hand-powered Pallet Jack.
To raise the forks of a Manual Pallet Jack, you push the actuating lever down and pump the handle up and down as you would trying to jack up a tire. Once the forks have been lifted, carrying the pallets that lay on them, you put the actuating lever in a neutral or middle position to move the load. Having the position neutral disengages the lifting mechanism and frees the handle from hydraulic resistance, but keeps the forks raised. To lower the forks you pull on the actuating lever to release the hydraulic resistance and the forks will lower back to the ground.
Manual Pallet Jacks are mostly used to move pallets from one place to another quickly, but rarely used to raise pallets to very high places.