A pump is a mechanical device that uses mechanical energy to move fluids or convert mechanical energy to hydraulic energy. It is commonly used to elevate fluids, pressurize fluids, or impart kinetic energy to fluids. A centrifugal pump has several key components, the most important being the impeller. The impeller rotates to impart centrifugal force and push liquid outwards. Impellers can be open, semi-closed, or closed depending on the type of liquid being pumped. Centrifugal pumps can be arranged either horizontally or vertically depending on space limitations, drive arrangements, and other requirements. Vertical pumps are now more commonly used due to better efficiency and space considerations compared to horizontal pumps.