Based on hydraulic and pneumatic design, a hand pump is usually operated by hand by the usage of a lever or handle. When external force is applied manually, it actuates an internal mechanism that increases pressure for moving fluids including water, chemicals, or gas. The hand lever is pushed in an up and down motion, which begins the pump cycle. Often one motion is required to draw the fluid and another motion is to release the fluid. This technique is typical for the operation of displacement pumps.

Hand pumps are capable of pulling water from practically any horizontal distance depending on the pressure that is applied to the lever by a manual external force. Hand pumps are lightweight, portable devices and can be used in marine applications, such as pumping seawater out from bilge. Hand pumps never require any type of electricity to be able to operate.