At the Fundamental level, the vast majority of Hindu religion followers believes that there is one supreme power who has hold of everything that exists in the Brahman(Universe).
At the same time, in Hinduism there are so many gods and goddesses, allowing individuals number of ways to worship based on family tradition, community and regional practices, and other practices.
But, in its core philosophy, all these Hindu deities are manifestations or avatars of the one supreme God.