At extreme high pressure, water is used in many industrial cleaning applications requiring the removal of surface coatings and for dust-free cutting of some metals and concrete. For exterior applications, gas powered washers provide greater mobility than electric ones, as they do not require use in proximity to an electrical outlet. For indoor applications, electric washers produce no exhaust and are much quieter than gas or propane washers.
The majority of pressure washers nowadays connect to an existing water supply, like a garden hose, but some models store water in an attached tank. Usually there is an on/off button that controls the water stream and many models allow you to adjust the water pressure.