pumps

Pump - Wikipedia, the free encyclopedia

To name a few:

Gear, piston, axial propeller, rotary screw, vane, centrifugal, peristaltic, progressive cavity, eductor, diaphragm.

For any of these types, add the word "pump" and Google or Wiki it. You can get lots of explanations.

In all cases, their function is to move a fluid from point A to point B.