In Sanātana, there are more than 33 million deities, but mostly are either tribal or just other names of the same deity. God in English, Allah in Arabic, Yahweh in Hebrew and Brahm(Brāhman) in Sanskrit(Saṃskṛta). The belief that Hinduism has many Gods is false. Those other Gods are merely celestial beings. The only God, Brahm is depicted as a vast ocean, not literally, each drop of Brahm ocean are souls. Just like the drops of water in the ocean are all same, likewise we are all same, we are all Brahm. To personify Brahm, in order to understand their actions, they(No male or female pronoun used) appear as three deities, Viṣṇu the preserver, Brahmā the creator and Śivā the destroyer. Viṣṇu is also an ultimate form of Brahm, or Parbrahma. The universe we live in was created by Brahmā. Basically, Brahmā is the universe in itself. There is not just one universe, but infinite, and thus infinite Brahmā. Lord Śivā has always existed, that's why he is also called Ādi-deva, which means always existing. These three deities are one, and collectively called Trimūrtī. All the deities are a part of Brahm, they are the forms of the Brahm only. Lord Viṣṇu always existed in his own realm, before anything.
There is a simple rule in physics, Magnetic poles are never independent, and this statement can help readers understand further.