Gautama differed with aspects of Hinduism such as the priest system,the caste system and the rituals.
He believed that the rituals of Hinduism could not lead to spiritual enlightenment and therefore urged for a focus in meditation, hence the birth of Hinduism. He also opposed the priest system and caste system ,but retained some aspects such as karma, dharma, moksha and reincarnation. simply put, Buddha asked people to seek spiritual enlightenment through meditation.