Pressure washers get categorized several different ways at once — by power source, by water temperature, by pump type, by duty rating — and shopping pages mix all four without explaining any. Here is each axis, plainly, with a note on whether it should affect your decision.
By power source
Corded electric
A mains motor driving a pump. Quiet, light, instant start, no maintenance beyond winterizing. Limited by what a household circuit supplies, which in practice caps you around 2,500 PSI and 2.0 GPM. This is what most homeowners should buy, and the picks are in the electric roundup.
Gas
A petrol engine driving a pump. More pressure and, crucially, more flow — 2.1 to 2.5 GPM at the entry level. Goes anywhere. Costs you fuel, oil changes, noise, weight and a pull start. Right for large properties; see the gas roundup and electric vs gas.
Battery / cordless
Battery-powered units exist and are improving. They are genuinely useful for rinsing bikes, muddy boots, kayaks and pets, away from any outlet. They are not pressure washers in the sense this site means: pressure and especially flow are well below a corded electric, and runtime is limited. Think of one as a very good portable rinser rather than a cleaning machine.
By water temperature
Cold water
Essentially everything sold to homeowners, including every machine on this site. Correct for dirt and biological growth, which is what a house actually has.
Hot water
Adds a heating element. Dissolves grease and wax, so it earns its place on engine bays, workshop floors, restaurant service areas and gum. Commercial equipment, expensive, usually rented. Covered in pressure washer vs power washer.
By pump type
Axial cam (direct drive)
The pump is driven straight off the motor or crankshaft. Simple, compact, cheap, and spinning at engine speed so it wears faster. Not usually serviceable. This is what nearly every consumer machine uses, and at homeowner duty cycles it is fine.
Triplex (belt or gear driven)
Three pistons, geared down to run slower and cooler, with serviceable seals and valves. Lasts vastly longer under continuous use and costs considerably more. This is the real difference between a consumer machine and a contractor one — more than the PSI figure is.
Should you care? Only if you are doing paid work. For a homeowner, an axial pump that is winterized properly and never run dry will outlast your interest in cleaning.
By duty rating
“Light duty”, “medium duty”, “commercial grade”. These are marketing terms with no agreed definition and should be ignored entirely. The honest proxies are flow rate, pump type and engine brand.
What this means for your decision
Two axes matter: power source and flow rate. Everything else is either commercial equipment you do not need, marketing with no content, or a durability question that correct maintenance answers. The decision order is in how to choose a pressure washer.
