An internal combustion engine is a type of engine that generates power by burning fuel inside a chamber. This process creates hot gases that expand and push against a piston, which then moves to turn the engine's crankshaft. Common fuels used in these engines include gasoline and diesel, making them popular in vehicles like cars and trucks. These engines are essential for many machines and transportation methods. They are found in motorcycles, boats, and even some generators. While they are efficient and powerful, internal combustion engines also produce emissions, leading to a growing interest in cleaner alternatives like electric engines.