Direct injection is a fuel delivery system used in internal combustion engines. In this system, fuel is injected directly into the combustion chamber under high pressure, allowing for more precise control of the fuel-air mixture. This can lead to improved fuel efficiency and reduced emissions compared to traditional fuel injection methods. This technology is commonly found in modern vehicles, including those powered by gasoline and diesel. By optimizing the combustion process, direct injection helps enhance engine performance and responsiveness, making it a popular choice among automotive manufacturers aiming to meet stricter environmental regulations.