Another Hindu term that is sometimes translated as deity is Ishvara, or alternatively various deities are described, state Sorajjakool et al., as "the personifications of various aspects of one and the same Ishvara". The term Ishvara has a wide range of meanings that depend on the era and the school of Hinduism. In ancient texts of Indian philosophy, Ishvara means supreme Self, Brahman (Highest Reality), ruler, king or husband depending on the context. In medieval era texts, Ishvara means God, Supreme Being, personal god, or special Self depending on the school of Hinduism.

Among the six systems of Hindu philosophy, Samkhya and Mimamsa do not consider the concept of Ishvara, i.e., a supreme being, relevant. Yoga, Vaisheshika, Vedanta and Nyaya schools of Hinduism discuss Ishvara, but assign different meanings.

Early Nyaya school scholars considered the hypothesis of a deity as a creator God with the power to grant blessings, boons and fruits; but these early Nyaya scholars then rejected this hypothesis, and were non-theistic or atheists. Later scholars of Nyaya school reconsidered this question and offered counter arguments for what is Ishvara and various arguments to prove the existence of omniscient, omnipresent, omnipotent deity (God).
As per the passage which schools of Hinduism discuss Ishvara?
Yoga, Vaisheshika, Vedanta and Nyaya.