Fuel injection is a system used in internal combustion engines to deliver fuel directly into the combustion chamber or intake manifold. This process replaces older carburetor systems, providing more precise control over the fuel-air mixture. By optimizing this mixture, fuel injection improves engine efficiency, performance, and reduces emissions. There are different types of fuel injection systems, including port fuel injection and direct fuel injection. Port fuel injection sprays fuel into the intake manifold, while direct fuel injection injects fuel directly into the combustion chamber. Both systems help engines run more smoothly and efficiently, contributing to better fuel economy and lower environmental impact.