Both Buddhism and Hinduism believe in an (almost) endless cycle of births, known as samsara. They also both seek release from this cycle of rebirths.
Hindus believe in an everlasting soul (atman) that is reincarnated more-or-less intact from birth to birth. Through spiritual practice, Hindus seek release (moksha, also known as liberation) so that the soul can join with the Universal Divine Force (Brahman, often simply translated as God).
Hinduism is the oldest religion