What are the defferences between dessel and petrol engine?

Petrol & Gas engines are spark ignited engines where as diesel engines are compression ignited engines. Petrol engines works with explosion of fuel air mixture due to spark from spark plug inside the cylinder. Diesel engines works with combustion of fuel air mixture due to compression, compressed mixture attains a very high temperature which exceeds the flash point of diesel and starts burning inside the cylinder and the hot gases after burning of fuel misture exerts force on piston which makes the diesel engines work. Diesel engines are highly efficient than petrol engines.