A Metering pump is a pump used to pump liquids at adjustable flow rates which are precise when averaged over time. Delivery of fluids in precise adjustable flow rates is sometimes called metering. The term "metering pump" is based on the application or use rather than the exact kind of pump used, although a couple types of pumps are far more suitable than most other types of pumps.

Dosing pumps are low-volume pumps with controllable discharge rates that are used to inject additives or difficult-to-mix fluids into mixing, pumping, or batch/tank systems. Dosing pumps are low-volume pumps with controllable discharge rates that are used to inject additives or difficult-to-mix fluids into mixing, pumping, or batch/tank systems.