What is the Difference Between A Gas Engine and A Diesel Engine?

Both Diesel and Gas Engines have the intake, compression, power and exhaust stroke cycle, where they differ in is the fuel type. Gasoline evaporates quickly in air and mixes well with compressed air and therefore can be easily ignited by a spark from a spark plug. Diesel fuel, on the other hand, is engineered to ignite at a high cylinder pressure without the need of spark plugs.