In Sanskrit, śakti means power, capacity, or ability. In Hindu religious thought it can refer to the effective power of a deity, the dynamic dimension of ultimate reality, or the Goddess herself. In goddess-centred Shakta traditions, Shakti is often understood not merely as an accessory of a male deity but as supreme divine reality, manifest in creation and spiritual liberation.
Other traditions may speak of the Shakti of Shiva, Vishnu, or another deity, and philosophical schools explain the relationship differently. Therefore “Shakti is energy” is a useful introduction but not a full definition: it should not be confused with a scientifically measured physical energy. The term belongs to a rich theological vocabulary in which divine presence, agency, knowledge and power may be inseparable.