In Buddhist cosmology, the concept of rebirth is central, signifying the cycle of birth, death, and rebirth known as samsara. This cycle is influenced by one's karma, the actions performed in previous lives. Rebirth occurs into various realms, including those of humans, animals, and spirits, reflecting the moral quality of past actions. Ultimately, the goal is to attain Nirvana, which is liberation from the cycles of rebirth, ending suffering and egoistic desires.