

Dashavatar refers to the ten avatars of Vishnu, the Hindu God of universal preservation. Dasa means 'ten' and avatara, means 'descent' or 'incarnation' . Lord Vishnu incarnates on Earth from time to time. All incarnations have a purpose, the protection of good, the destruction of evil and the establishment of Dharma.
Jayadeva enumarates ten incarnations of Lord Vishnu in Geeta Govinda…..
1. Matsya (The Fish)- At first the whole of the creation was full of water. Sages of the past say that the fish was the first aquatic creature created by God. Due to spark of Chidatma infused in it, it throbbed into life and it is considered to be the Fish incarnation of God, who decended to earth to teach people and to preserve His creation. The Vedas were in danger. Lord Vishnu takes the form of a fish to save the Vedas. The goal was ro control the mind and focus it on knowledge of Brahma, the Ultimate Reality.
2. Kurma (The tortoise)- Kurma appeared when the Devas and Asuras were churning the Ocean of milk in order to get Amrita, the nectar of immortality, the mount Mandara they were using as the churning staff started to sink and Lord Vishnu took the form of a tortoise to bear the weight of the mountain.
3. Varaha (The boar)- Varaha appeared to defeat Hiranyaksha, a demon who had taken the Earth, or Prithvi, and carried it to the bottom of what is described as the cosmic ocean in the story. The battle between Varaha and Hiranyaksha is believed to have lasted for a thousand years, which the former finally won. Varaha carried the Earth out of the ocean between his tusks and restored it to its place in the universe.
4. Narasimha(The half-man half-lion)- The rakshasa(An evil person) Hiranyakashipu, the elder brother of Hiranyaksha, was granted a powerful boon from Brahma, not allowing him to be killed by man or animal, inside or out, day or night, on earth or the stars, with a weapon either living or inanimate. Vishnu descended as an anthropomorphic incarnation, with the body of a man and head and claws of a lion. He then disembowels the rakshasa at the courtyard threshold of his house, at dusk, with his claws, while he lay on his thighs.
5. Vamana (The Dwarf)- The fourth descendant of Hiranyakashyap, Bali, with devotion and penance was able to defeat Indra, the god of firmament. This humbled the other deities and extended his authority over the three worlds. The gods appealed to Vishnu for protection and he descended as the dwarf Vamana. During a yajna of the king, Vamana approached him in the midst of other Brahmins. Bali was happy to see the diminutive holy man, and promised whatever he asked. Vamana asked for three paces of land. Bali agreed, and the dwarf then changed his size to that of a giant. He stepped over heaven in his first stride, and the netherworld with the second. Bali realized that Vamana was Vishnu incarnate. In deference, the king offered his head as the third place for Vamana to place his foot. The avatar did so and thus granted Bali immortality.

6. Parashurama (Rama with the axe)- Parasurama received an axe after a penance to Shiva. Parashurama is the first Brahmin-Kshatriya in Hinduism, or warrior-saint, with duties between a Brahmana and a Kshatriya. Most of the kshatriyas who were the ruling chiefs of the country were despots and did not care for the welfare of the people. They practiced all sorts of cruelties. In order to save his creation from disaster God again incarnated Himself as Parasurama and after eliminating these kshatriyas He restored peace and order on the earth.
7. Rama (Ramachandra, the prince and king of Ayodhya)- Rama is a commonly worshiped avatar in Hinduism, and is thought of as the ideal heroic man. His story is recounted in one of the most widely read scriptures of Hinduism, the Ramayana. While in exile from his own kingdom with his brotherLakshman and the monkey king Hanuman, his wife Sita was abducted by the demon king of Lanka, Ravana. He travelled to Ashoka Vatika in Lanka, killed the demon king and saved Sita.
8. Balarama (Also known as Haladhara) - Balarama is the elder brother of Krishna (an avatar of the god Vishnu) and is regarded generally as an avatar of Shesha. He is also sometimes considered as the Sankarshana form of Vishnu and the eighth avatar of Vishnu.
9. Buddha - Due to Vedic complexities of mode of worship to God, the rigidness of the caste system and other superstitions prevalent in the society, people were subjected to great oppression and ill-treatment. Animal sacrifice in the 'Yagna' and many other cruelties were practiced in the name of God. To eradicate this blemish from the human society, God incarnated Himself as Buddha and taught people the rare virtues of truth and non-violence.
10. Kalki (Eternity or White Horse, or Destroyer of Filth)- Kalki is the final incarnation of Vishnu, foretold to appear at the end of Kali Yuga, our present epoch. He will be atop a white horse and his sword will be drawn, blazing like a comet. He is the harbinger of end time in Hindu eschatology, and will destroy all unrighteousness and evil at the end of Kali Yuga.