Pressure washers are powerful outdoor cleaning machines. They produce high pressure water streams while their different nozzles remove dirt, debris and stubborn stains from paths, driveways, decks, vehicles, boats and sheds. They can even clean home exteriors and windows. Pressure washers come in many sizes and pressure outputs and have an array of built-in, on-board features and accessories. Consequently, some are better suited to certain tasks than others. Knowing what you want to use a pressure washer for will help in your purchasing decision.