A diesel engine is a type of internal combustion engine that uses diesel fuel to operate. Unlike gasoline engines, which ignite fuel with a spark, diesel engines compress air to a high temperature, causing the diesel fuel to ignite when injected. This process makes diesel engines more efficient and powerful, often used in heavy-duty vehicles like trucks and buses. Diesel engines are known for their durability and fuel efficiency, making them popular in various applications, including ships, generators, and construction equipment. They typically produce more torque than gasoline engines, which is beneficial for tasks requiring heavy lifting or towing.