Pre Vedic period ( before 2,000 B.C) :
The inhabitants of the Indus Valley worshipped aspects of nature like wind, water, earth, heaven, mountains etc.
Vedic period :
With the invasion of the Aryans these aspects of nature got more and more the shape of humans and animals.
During time several gods and goddesses had to give up there prominent place to other gods and goddesses. In the early writings we find 3 gods, later 33 gods up to 330 million gods.
The Hindu principle “There is one God, but there are many Gods” can be best used.
Different Hindu communities may have their own divinities whom they worship, but these are simply different ways of approaching the Ultimate. The gods of the Hindu faith represent different expressions of Brahman.
There is thus one God, who can take several Devine shapes.