Kain, also known as Cain, is a biblical figure from the Book of Genesis in the Hebrew Bible. He is recognized as the firstborn son of Adam and Eve. Kain is known for his role in the story where he becomes envious of his brother Abel, leading to the first murder in history when he kills Abel out of jealousy. After the murder, Kain is marked by God to prevent others from killing him. He then becomes a wanderer, settling in the land of Nod. Kain's story is often interpreted as a cautionary tale about the consequences of jealousy and violence.