There are 6 diffrent main beliefs that shape Hinduism into the religon that it is. Hindu revolve around these ideas. Hinduism is very old and historians dont know when it started. Early Hindu religion is called Vedism after the Vedas which are sacred texts of Hindu reigion. Over time priests and religious scholars called Brahmins were the only ones who could inturpret the vedas and perform vidic rituals. Today they are the highest class in Hinduism.
Here is a picture representing these six beliefs:
The first belief is Brahman. According to Hinduism, Brahman is the supreme force in the universe. Brahman is the only thing that exists forever. Everything in the world including the soul is part of Brahman. Hindus connect with Brahman and the rest of their deitites through visiting temples and bathing in rivers such as the Ganges.
Many Deities exist in Hindu sacred texts. Today the most important Deities are Vishnu, Shivia and Braham. Each of these controls one characteristic of the universe. Hindu sacred texts sometimes tells stories about Dieties fighting evil.
Dharma is very important to Hinduism. It stands for law, obligation, and duty. To follow your dharma is to live as one should. Because Hinduism was structured into classes of society, as long as you followed your dharma society would live peacefully. Also, by following someone's varna Dharma ("the way of one's kind") there are basic values to follow like nonviolence.
Karma keeps things fair according to the Hindus. Karma decides what happens to peoples souls after death. If people had good Karma, what they had done in past lives they would get reborn into a good social class. If one ended up in a low part of society it would be fair because it would reflect on what they have done in past lives.
The last Hindu belief is samsara. It is the countiuous cycle of birth, death and rebirth. When people are in Samsara they will suffer from pain and death. People escape from samsara when they are reunited with Brahman. It will take a long time to be released but in order to do so you must fallow basic beliefs of Hinduism. Since you have to reunite with Brahman the Hindus do things like make holy journeys to strengthen their connection with Brahman.