First of all , there is no Hindu religion as such.
Vedic culture is one thing and whatever way , India has evolved in past 5000 years is another thing.
Problem is so much confusion , as when we studied in school, nobody gave us correct information. Even today, in school texts , there is restricted info. Thank God, Google happened.
I will give you few example.
Do you know, what were we eating before 1947 ?
How Indians were living life before 1947 ?
What was social fabric of India ?
Nobody has any documented literature. If there is any good stuff, its lying in so called National Libraries. I don’t understand , why nobody puts it in ebook form for present generation.
If we go through ancient texts and authorised documents, then we realise, we were not told any thing. There is no culture as Hindu culture, the word Hindu has evolved over centuries.
The term Hindu implied a geographic, ethnic or cultural identifier for people living in Indian subcontinent around or beyond Sindhu. It got prominent during British era, when they start calling basic Indians as Hindu , Mohamedans for Mughals and Arabs as Islamist.
You can visit this link for history of word Hindu
Basically, in old days it was Southern India and Northern India, which were following same religion and structure , though as different names and customs. Syncretism of various traditions and Vedism resulted in Vaishnavism. Vaishnavism is centered on the devotion of Vishnu and his avatars. The term “Krishnaism” has been used to describe the sects focused on Krishna, while “Vishnuism” may be used for sects focusing on Vishnu in which Krishna is an avatar of Vishnu.
It diversified into Gaudiya Vaisnavism , Nimbarka ,Vallabhacharya etc.
The story is still going on