In Buddhism, rebirth is called samsara. Samsara means "wandering." It is believed that samsara is the main source of suffering and it's Buddhist's goal is to escape the suffering. It is very difficult to find the way out of samsara and achieve enlightenment, and people go through many lives trying to perfect themselves. A large par of rebirth is karma
Karma is good actions and bad actions a person does during their lifetime. it is believed that good actions will bring a better life in your next life. Supposedly, bad actions will bring a bad life in your next life.