This can be rather confusing, but all of those terms mean the same thing, with some minor differences. A pressure washer gun and trigger gun are basically the same. But on the other hand, a wand and a lance, which are usually used interchangeably to represent a standard pressure washer gun, actually have a small difference. A lance or wand is used when a pressure washer gun has an integrated longer output nozzle. So the to long didn’t read (TLDR) – A pressure washer gun and trigger gun is the same, a lance or rather a wand, can be used to represent a pressure washer gun which has an integrated longer nozzle.