A fuel injector is a crucial component in modern engines that helps deliver fuel to the engine's combustion chamber. It sprays a precise amount of fuel into the air intake or directly into the combustion chamber, ensuring the engine runs efficiently. This process is controlled by the engine's computer, which adjusts the fuel flow based on various factors like speed and load. By using a fuel injector, vehicles can achieve better fuel efficiency and lower emissions compared to older systems like carburetors. This technology is found in many types of vehicles, from cars to trucks, making it an essential part of the automotive industry.