Wikipedia
Treta Yuga ( Devanagari: त्रेता युग) is the second out of the four yugas, or ages of mankind, in the religion of Hinduism. It follows the Satya Yuga and is followed by the Dvapara Yuga and Kali Yuga. Treta means 'a collection of three things' in Sanskrit, and is called so because during the Treta Yuga, there were three Avatars of Vishnu that were seen, the fifth, sixth and seventh incarnations as Vamana, Parashurama and Rama respectively. The name could also be derived from the fact that the Treta Yuga lasts 3,000 divine years. The Dharma bull, which symbolises morality, stood on three legs during this period. It had all four in the Satya Yuga and two in the later Dvapara Yuga. Currently, in the immoral age of Kali, it stands on one leg. The Treta Yuga lasted 1,296,000 years.