A supercharger is an air #compressor that increases the #pressure or density of air supplied to an internal combustion #engine.
This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power.
Power for the supercharger can be provided mechanically by means of a belt, gear, shaft, or chain connected to the engine’s crankshaft
Some times we add air cooler after the compressor output to cool the compressed air and increase its density .It called #intercooler
See also #turbocharger