A Hindu philosophical concept of God referring to the Supreme Being which is the lord and the ruler of everything. Hinduism uses the term Ishvara exclusively to refer to the Supreme God in a monotheistic sense.
Ishvara (Sanskrit: Īśvara) is a concept in Hinduism, with a wide range of meanings that depends of the era and the school of Hinduism. In ancient texts of Indian philosophy, Ishvara means supreme soul, 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.
In Shaivism, Ishvara is synonymous with "Shiva", as the "Supreme lord over other Gods" in the pluralistic sense, or as an Ishta-deva in pluralistic thought. In Vaishnavism, it is synonymous with Vishnu. In traditional Bhakti movements, Ishvara is one or more deities of an individual's preference from Hinduism's polytheistic canon of deities. In modern sectarian movements such as Arya Samaj and Brahmoism, Ishvara takes the form of a monotheistic God. In Yoga school of Hinduism, it is any "personal deity" or "spiritual inspiration". In Advaita Vedanta school, Ishvara is a monistic Universal Absolute that connects and is the Oneness in everyone and everything.