A pump is a device used to raise, transfer, or compress liquids and gases. Water is a typical fluid used by pumps in applications such as irrigation and cooling, among others.
Applications involving air are often where a vaccum is needed.
Even an average leaf blower pumps air out in a focused stream in order to clear leaves from a particular area. Another very typical use of a pump is to force gas into a combustion chamber such as in a jet engine, where it is termed a compressor. Multitudes of uses have been discovered for pumps involving liquids varying from blood to sludge. Although a pump can be used with almost any liquid, certain attributes of the working fluid must be considered when designing a pump. For example, if the pump must displace an acidic fluid, the pump must be composed of materials which will not react with the acid.