Some hydraulic pumps are manual and some are powered by electricity, compressed air or petrol. Manual hydraulic pumps are great because they have portability because they don't need an additional power supply. They are perfect for occasional tasks but they do lack the power and speed of powered pumps. They are also labour intensive.

Electric and pneumatic pumps are both good when the required power source is to hand. They will get more done in a quicker time than a manual hydraulic pump but the downside is their cost and the fact that they have to be powered by air or electricity and so the supply must be near to hand.

Petrol pumps are good for situations where a manual pump is not powerful enough and where the constraints of a pneumatic or electric pump don't allow for use in remote places.

Hydraulic pumps have all sorts of uses but if you find that you need to buy one yourself, make sure that you do your research and get the right one.