Difference between turbocharging and supercharging

A supercharger is an air compressor used for forced induction of an internal combustion engine. The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine. Supercharger allows more fuel to be burned and more work to be done per cycle, increasing the power output of the engine. Power for the unit can come mechanically by a belt, gear, shaft, or chain connected to the engine's crankshaft.

A turbocharger or turbo is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine (forced induction), thereby resulting in greater performance (for either, or both, power and efficiency). They are popularly used with internal combustion engines.

Supercharging and turbocharging are similar in process and differ in operation, it means, both are used for same purpose i.e to increase engine power, efficiency, torque by compressing the air in multistage for increasing quantity of air, pressure and temperature. But the difference is ,

In turbocharging, the exhaust gases from the engine cylinder is used to drive the turbine. The turbine and compressor are mounted on the same shaft. When the exhaust gases are passed through turbine, the turbine rotates as the gases import heat energy, hence the turbine produces mechanical energy i.e rotation of shaft for driving compressor. Now the compressor also rotates to compress the inlet air to the cylinder. The inlet air is compressed before reaching engine cylinder.

In supercharging, the rotation of crank shaft is used to drive the turbine through gears and chains or pulleys and belts. The turbine and compressor are mounted on the same shaft. When the crank shaft rotates, the shaft of the turbine also rotates since both are connected mechanically through gear and chain or pulley and belt arrangements. Hence the turbine produces mechanical energy i.e rotation of shaft for driving compressor.