Buddha accepted the basic Hindu doctrines of reincarnation and karma, as well as the notion that the ultimate goal of the religious life is to escape the cycle of death and rebirth. Buddha asserted that what keeps us bound to the death/rebirth process is desire, desire in the sense of wanting or craving anything in the world. Hence, the goal of getting off the Ferris wheel of reincarnation necessarily involves freeing oneself from desire. Nirvana is the Buddhist term for liberation. Nirvana literally means extinction, and it refers to the extinction of all craving, an extinction that allows one to become liberated.
Where Buddha departed most radically from Hinduism was in his doctrine of "anatta", the notion that individuals do not possess eternal souls. Instead of eternal souls, individuals consist of a "bundle" of habits, memories, sensations, desires, and so forth, which together delude one into thinking that he or she consists of a stable, lasting self. Despite its transitory nature, this false self hangs together as a unit, and even reincarnates in body after body. In Buddhism, as well as in Hinduism, life in a corporeal body is viewed negatively, as the source of all suffering. Hence, the goal is to obtain release. In Buddhism, this means abandoning the false sense of self so that the bundle of memories and impulses disintegrates, leaving nothing to reincarnate and hence nothing to experience pain.
From the perspective of present-day, world-affirming Western society, the Buddhist vision cannot but appear distinctly unappealing: Not only is this life portrayed as unattractive, the prospect of nirvana, in which one dissolves into nothingness, seems even less desirable. A modern-day Buddha might respond, however, that our reaction to being confronted with the dark side of life merely shows how insulated we are from the pain and suffering that is so fundamental to human existence.