All Pressure Washer is power spray systems have a gasoline or electric motor that powers a water pump. The water pump works by drawing water into the pump housing through an inlet hose connected to a water source such as a garden hose. As the pump shaft rotates, it pressurizes the water that is then forced out of the pump under high pressure. The water then travels through the hig... https://medium.com/@prachicmi1/pressure-washer-understanding-power-spray-systems-your-guide-to-cleaning-with-high-pressure-water-207c108ea096