Aspirator (pump)
An aspirator, is a type of ejector-jet pump, that produces vacuum by means of the Venturi effect.
In an aspirator, fluid (liquid or gaseous) flows through a tube which then narrows. When the tube narrows, the fluid's speed increases, and because of the Venturi effect, its pressure decreases. Vacuum is taken from this point.
Read more about Aspirator (pump): Operation