Pumps are used to add energy to fluids (gases, liquids, or slurries) in order to produce flow or increase pressure. They can perform many different functions, including moving a fluid from one location to another, recirculating a fluid in a closed system, such as in a heating or cooling system, and providing pressure, such as in hydraulic systems. These functions are performed primarily by two different types of pumps: centrifugal and positive displacement. This module describes the most common types of pumps and their applications.