What is the difference between a power washer and a pressure washer?

The terms "pressure washer" and "power washer" are generally used interchangeably. Among contractors and online discussions, there is generally no distinction made between the two terms. One pressure washer manufacturer, Hydrotek, does make a distinction, however. On their website, Hydrotek states that a the term power washer" is usually used to denote a light duty pressure washer.