A hybrid vehicle uses two or more distinct types of power, such as internal combustion engine to drive a generator that powers an electric motor, e.g. in diesel - electric trains using diesel engines to drive an electric generator that powers an electric motor, and submarines that use diesels when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids.
where does a hybrid vehicle store its energy
batteries pressurized fluid