A basic definition of a two-stage air compressor is a heavy-duty air compressor that uses two cylinders to create more power. An air compressor is a device that increases the amount of air in a confined space. Confined air builds pressure and generates power for industrial, commercial and personal uses. The two-stage air compressor comes with two pistons. One pumps air from one cylinder to a second cylinder, and this increases the air pressure for generating the amount of power necessary for the equipment. Want to see just how it works? Watch the excellent Doosan Portable Power video below. Enjoy.