Introduction to Jataka Tales (Chadok Tales)
For Buddhism, all people, all animals, and all lives are in a cycle of rebirth and death. Most people are stick with pleasure (Karma) so that they can’t get out of this cycle.
The Buddha is the one who can deeply realized the cycle and can get out of the cycle by put his mind in a state of nirvana. He tried to warn us and guide us to get away from the cycle.
Same as other people, the Buddha have ever been a man, a woman, a king, a merchant, a monkey, a cow, and many kinds of animal. He need to collect good deeds (Boon) for many lifetimes before he can get out of the cycle.
Jataka tales are stories about previous lifes of Buddha. There are about 500 stories told in Tipitaka.