That addicting dark liquid that we drink is made by different types of machines. One of these Espresso Makers is the Pump Method machine.

This machine will pump water automatically into a tank to build up enough pressure to force the water through the coffee grounds. Water pressure and temperature are kept at optimum levels to ensure a good cup of espresso.
Some machines already have pressure and temperature gauges so that you can make sure they are at the right levels.

This type of machine usually provides better quality at a mid-level price. Prices are noticeably higher than steam machines and the labor is more hands-on, but the quality of the cup of espresso is definitely better.