Non-theistic monism, which probably makes no sense whatsoever
Basically it says that there is no such thing as a personal God (like in the Abrahamic religions), but something called Brahman which is essentially an abstract Cosmic Principle which manifests as this entire universe and everything within it.
The clearest vision of this Principle is humanity. Discovering that Principle/Divinity within yourself is the main aim of this branch and also happens to be free of binding doctrines and dogmas.
You can adopt a variety of different pathways to achieve this - it could be through charity work or Yoga or gaining knowledge through science, literature, poetry, maths; or even through simple things like listening to music or playing sport.
Discovering this inner Self is not limited to one or two pathways, but can manifest itself through any disciplined human endeavour. As many humans, that many ways of discovering the Principle/Brahman. As such, it's very pluralist in its outlook.