Compare gas and electric pressure washers
Gas: These are more powerful than electric. They have an added cost of buying gas, oil and spark plugs. They are also a lot louder than electric ones. Gas pressure washers are more mobile and powerful for larger jobs.
Electric: These have restricted movements. The electric motors are the limiting factor on their lifespan (they are more prone to overheat and short out). Electric pressure washers are also a lot lighter than gas ones. Electric pressure washers cost less and are also less powerful and mobile than a gas washer. However, they are ideal for light-duty jobs.