A vacuum pump is a piece of machinery that creates a partial or low-pressure vacuum by pushing gas or air molecules out of a sealed chamber. A vacuum is a relative state in which the chamber pressure is lower than that of the surrounding atmosphere or systems. This is distinct from absolute vacuum, which has a pressure of 0 Pa and is free of gas molecules.
Atmospheric pressure, or the weight of air pressing down on the earth, is a critical component of a vacuum pump. This pressure is caused by the weight of air molecules, which decreases as altitude increases. The operation of machinery, particularly hoover pumps, is heavily influenced by air pressure or atmospheric pressure. As molecules move from high to low areas to fill a space, pressure always attempts to equalise, a process based on the idea of pushing molecules.
