Ishvara (Sanskrit: ईश्वर, Īśvara) is a concept in Hinduism, with a wide range of meanings that depend on the era and the school of Hinduism. In ancient texts of Indian philosophy, depending on the context, Ishvara can mean supreme soul, ruler, lord, king, queen or husband. In medieval era Hindu texts, depending on the school of Hinduism, Ishvara means God, Supreme Being, personal god, or special Self.
In Shaivism, Ishvara is synonymous with "Shiva", sometimes as Maheshvara or Parameshvara meaning the "Supreme lord", or as an Ishta-deva (personal god). In Vaishnavism, it is synonymous with Vishnu...