A turbocharger is a device that increases the power output of an engine by forcing additional air into the combustion chamber. This additional air increases the fuel-air ratio, which allows the engine to burn more fuel and produce more power. Turbochargers improve engine performance by increasing the engine's power output, improving fuel efficiency, and reducing emissions. Additionally, turbochargers can reduce turbo lag, which is the delay between pressing the accelerator and the engine responding.