Vishnu Dashavatara

As per Hindu Mythology, Lord Vishnu is the protector, preserver and patron of this life. He is considered the holiest of all the gods. He resides in the highest heaven described as Vaikuntha. He has tranquillity in his countenance, lotus shaped eyes and skin, blue as the sky. His four arms holds a conch, a mace, a chakra and lotus which are representative of the four directions of the cosmos, he protects. In four hands he holds. Whenever the sacred, moral and ethical norms of Dharma are broken and chaos and evil threaten the universe, Lord Vishnu incarnates into the world and re-establishes harmony by fighting the forces of disorder. All the incarnations have a common purpose protection of the good, destruction of evil and establishment of Dharma.

The word Dashavatara derives from ‘dasa’, meaning ten and avatar meaning incarnation. Dashavatara refers to the ten avatars of Lord Vishnu. The first four avatars of Vishnu appeared in Satya or Krita Yuga, the first of the four yugas. The Satya Yuga is also known as The Golden Age. The next three Vishnu incarnations appeared in Treta Yuga. The eighth and ninth forms in Dwapara Yuga and the tenth avatar are believed to appear in Kali Yuga.

Source: https://www.brihaspatipuja.org/vishnu-dashavatara.html