Overview
Yama (Sanskrit: यम, meaning 'twin'), also known as Kāla and Dharmarāja, is the Hindu god of death and justice. In Hindu tradition, he is responsible for the dispensation of law and the punishment of sinners in his abode, Naraka. He is often identified with Dharmadeva, the personification of Dharma, though the two deities have distinct origins and associated myths.
In the Vedic tradition, Yama is regarded as the first mortal who died and discovered the way to the celestial abodes; consequently, he became the ruler of the departed. His role, characteristics, and abode are expounded in texts such as the Upanishads, the Ramayana, the Mahabharata, and the Puranas. He is described as the twin of the goddess Yami and the son of the sun god Surya (in earlier traditions Vivasvat) and Sanjna.
According to these traditions, Yama judges the souls of the dead and, depending on their deeds, assigns them to the realm of the Pitris (forefathers), to Naraka, or to rebirth on the earth. He is counted among the Lokapalas, the guardians of the realms, and is appointed as the protector of the southern direction. In iconography, he is often depicted as a dark-complexioned figure riding a buffalo and carrying a noose or mace, used to capture the souls of the departed.
Beyond Hindu tradition, Yama was subsequently adopted into Buddhist, Chinese, Tibetan, Korean, and Japanese mythologies as the king of hell. In modern Indian culture, the figure of Yama has also featured in various public safety campaigns.
References
Adapted from the English Wikipedia article on Yama.