A turbocharger, or turbo is a forced induction device used to allow more power to be produced for an engine of a given size. The key difference between a turbocharger and a conventional supercharger is that the latter is mechanically driven from the engine often from a belt connected to the crankshaft, whereas a turbocharger is driven by the engine's exhaust gases. A turbocharged engine can be more powerful and efficient than a naturally aspirated engine because the turbine forces more intake air, proportionately more fuel, into the combustion chamber than if atmospheric pressure alone is used.

Turbos are commonly used on truck, car, train and construction equipment engines. Turbos are popularly used with Otto cycle and Diesel cycle internal combustion engines. They have also been found useful in automotive fuel cells. Twincharger refers to an engine which has both a supercharger and a turbocharger.