Internal Combustion Engine refers to which the air-fuel mixture gets burned.
An engine is a machine that converts heat energy into mechanical energy. The heat from burning fuel produces power that moves the vehicle. Sometimes, the engine is called the power plant. Automotive engines are internal combustion engines because the fuel that runs them is burned internally or inside the engine. There are two types, reciprocating and rotary. Reciprocating means moving up and down or back and forth. Most automotive engines are reciprocating. They have pistons that move up and down or reciprocate in cylinders. These are piston engines. Rotary engines have rotors that spin or rotate.