Shri Vishnu Incarnations - Dashavatar - 24 Incarnations

Shri Vishnu Incarnations (Avatars)
The word “Avatar”, a Sanskrit word means “descent”. In Sanatana Dharma it means the Descent/Incarnation/Manifest/Appearance of Lord/Supreme Being/Deity in an earthly embodiment.

The concept of Avatar in Sanatana Dharma mostly related to Lord Vishnu, one of The Trinity. Srimad Bhagavatam described the innumerable Lord Vishnu’s Avatars, mostly The Ten Incarnations (Dashavatara) are widely known. And among them Lord Shri Rama (related to Ramayana) and Lord Shri Krishna (related to Mahabharata) are widely worshiped Avatars of Lord Vishnu. In Srimad Bhagavatam, around 24 different Avatars of Lord Vishnu are discussed that were descended in different Yugas.

There is no reference of Avatar exists in Vedas. The Bhagavad Gita discusses the subject matter associated with Avatar in textual format in Chapter 4 Slokas 5~9, where Lord Shri Krishna Himself declared the role of taking Avatar.

Whenever and wherever there is a decline in religious practice, O descendant of Bharata, and a predominant rise of irreligion — at that time I descend Myself. To deliver the pious and to annihilate the miscreants, as well as to reestablish the principles of religion, I Myself appear, millennium after millennium. (Bhagavad Gita Chapter 4 Verses 7~8)

Classifications of Avatars:

Avatar, incarnations are broadly classified into two kinds. When Lord Vishnu Himself descends on earth, He is called Sakshaty-Avatara, and when He indirectly empowers some living entity to represent Him, than that living entity is called an Avesa-Avatara.

Direct (Sakshaty): Lord Krishna, Lord Rama, Lord Narasihma etc.
Indirect (Avesa): Narada Muni, Parashurama, VayasDeva etc.

Sakshaty or Direct Avatars are further classified into two more categories:

Purna Avatar: Lord Visnhu takes form directly and all the qualities and powers of God are expressed. (Lord Rama, Lord Krishna, Lord Narasimha)

Amsarup Avatars: Lord Vishnu takes form directly but He is manifest in the person only partially (Matsya, Kurma, Varaha )

Lord Krishna is highest Purana Avatar.
Various Incarnations of Lord Vishnu as per Srimad Bhagavatam:

The details of about 24 incarnations of Lord Vishnu are mentioned in Srimad Bhagavatam:
Canto 1: Chapter 3: Verses 1~25.

Adi Purush Avatar

Lord Vishnu having desire to commence creation, took first avatar, incarnation as the pre-eminent man (with all his sixteen Kalas). The first incarnation is full of Super Natural Powers, Indestructible Seed from which all other incarnations manifested. While lying on Adi Sheesh (Seesh Naag), Lord Vishnu in state of Yoganidra (deep meditation), manifested Lord Brahma from His navel, and then so on, The Creation commenced from the organs of Lord Brahma.

The Four Kumaras (ChaturSana)

The Four Kumaras are the first mind-born (ManasPutra, born by wish) creation of Lord Brahma, who exemplifies the path of devotion by being remain in the state of celibacy throughout their life. The name of Four Kumaras are: Sanaka (Ancient), Sanatana (Eternal), Sanandana (Joyful), and Sanatkumara (Ever Young). The Four Kumaras practiced the vow of Renunciation (Sanyasa), Celibacy (BrahamCharaya) and signifies the importance of Penance. They are well versed in the context of Vedas and they underwent severe austerities for the realization of Absolute Truth.   

Varaha Avatar (The incarnation as Boar)

The demon Hiranyaksha abducted the Mother Earth (bhumi devi) and took her to the Paatal Lok, deep under the ocean. He also stole the Divine Vedas from Lord Brahma while he was in deep meditation. The Lord Vishnu took the incarnation of Varaha Avatar and rescued the Mother Earth which had submerged in the ocean, and brought the Earth out by lifting it on His Two Tusks from the ocean after killing the demon Hiranyaksha. Lord Vishnu in Varaha Avatar also retrieved the Divine Vedas from the demon and gave it back to Lord Brahma. 

Sage Narada Avatar

Devarishi Narada the best among demigods, achieved liberation from all his Karmaic Actions mere by simple Devotion. Lord Vishnu in the incarnation of Devarishi Narad signifies the importance of Devotion. Devarshi Narad is depicted carrying the musical instrument called Veena which he used to play, to glorify the name of Lord Vishnu (Narayana) out of devotional love for Him. The Narada Bhakti Sutra is attributed to Devarishi Narad. Devarshi Narad is both wise and mischievous, and can be regarded as first Journalist as he was the prime source of information among Demi-Gods.
(Note: Narada is considered as Sakshaty avatar, partial manifestation of Lord Vishnu, who empowered him to enhance the significance of Devotional Love).

Nara-Narayana (Twin Sages) Avatar

The twin-brother incarnation of Lord Vishnu on Earth to preserve the Dharma, Righteousness; the human soul Nara is the eternal companion of Divine Narayana. Nara-Naryana performs several penances at the holy spot of Badrinath. The two inseparable sages took avatar on earth for the welfare of humankind. Arjuna and Krishna (from Mahabharta), are referred reborn as Nara-Naryana.

Kapila Avatar

The great sage born of the Kardama muni and Devahuti; the objective of this incarnation was to compile the divine knowledge that had been disappeared. Lord Kapila is the founder of Sankhya philosophy (Duality of Prakriti and Purush). Lord Kapila gave discourse to his mother Devahuti (first disciple) famous as Lord Kapil’s Teachings. Lord Kapila is known for teaching a process of liberation known as Bhakti Yoga           

Dattatreya Avatar

The combined avatar of Trinity, (Brahma-Vishnu-Shiva), born of Sage Atri and Devi Anusya; Lord Dattatreya has 24 Gurus, and he believed that in this world one can learn from each and every thing, such as from Earth, Water, Ocean , Fire, Bird, etc. Lord Dattatreya gave the Spiritual knowledge to King Prahlada and King Alarka.

Yagya (Yajna) Avatar

The lord of fire sacrifices, born of Prajapati and Akuti; Yajna rescued the Devgana (Celestial and Super Natural Being). During the era of Svayambhuva Manvantran, having no qualified Indra for the post of King of Swarga (Heaven), the Lord Vishnu Himself incarnated as Yajna and held the post of Indra. The main teaching of Yajna avatar was based on the values of helpfulness and protecting each other during the time of crisis.

Rishabh Avatar

Rishabh Dev was born to King Nabhi and Marudevi (Daughter of Indra). Rishabh Dev attained the state of Paramhansa, as ascetic of highest order who has controlled the anger. Also Rishabh Dev was given the title of “Jin” which means “a Knower”. In this incarnation Lord Vishnu showed the path of Perfection, which is followed by those who have fully controlled their senses and who are honored by all orders of life. The utmost important teaching to the mankind from Rishabh Dev is, “material possessions cause envy and unhappiness”. 
Prithu Avatar

One the prayer of sages, the Lord Vishnu incarnated as King Prithu on Earth, who cultivated the Earth Land to yield various produces and for that reason the earth is so beautiful and attractive.
The mother Earth had become barren after concealing all the vegetation within her, so to protect the humanity, Lord Vishnu took incarnation as Prithu. Prithu is mainly associated with the legend of his chasing the earth goddess, Prithvi, who fled in the form of a cow and eventually agreed to yield her milk as the world's grain and vegetation. This is considered that as a very supreme incarnation, because the earth has remained full of vegetation's after that. The Sanskrit name Prithvi (Earth) comes from Prithu.
Note: Prithu is born without any female intervention. He is born of corpse of King Vena.

Matsya Avatar  ~ Fish Incarnation

At the earlier stage of Sat Yuga, Lord Vishnu appeared in the form of fish, and predicted to the King Manu, that world would come to an end by huge flood in seven days. Lord Vishnu in the form of Matsya Avatar instructed the Lord Manu to build a huge boat and took Seven Sages (SaptRishis), seeds of all plants, one animal type of each species etc. Lord Vishnu further instructed that He Himself will appear as the form of fish and will propel the boat to Mount Himavan to save them from flood. The prediction comes true, after seven days huge flood come, and Lord Vishnu in the form of Matsya Avatar protected those who were on the boat. Matsya Avatar is associated with beginning of the world.

Kurma (Kachchap) Avatar ~ Tortoise Incarnation

This incarnation is associated with the very famous churning of the ocean (Saagar Manthan) story. While the Devas and Asuras were churning the ocean for the nectar of immorality, the mountain Mandarachala they were using began to sink in the soft ocean floor, so Lord Vishnu became a turtle and rested the mountain on his back to keep the mountain afloat.

Dhanvantari Avatar ~ Lord of Medicine

Lord Vishnu manifested in the avatar of Dhanvantari from the Sagar Manthan, holding a vessel filled with important Medicines (Herbs). Dhanvantari was the profounder of Medical Science (AyurVeda). Dhanvantari emerged from Ocean of Milk (Sagar Manthan), holding Medical Herbs in one hand, and pot containing the Amrita (Rejuvenating Nectar).

Mohini Avatar ~ Enchanting Woman

This is the only female incarnation of Lord Vishnu. Lord Vishnu incarnated as most enchanting woman, enchanted the Asuras (Demons) by her beautiful appearance and trick-fully, she theft the Amrita Vessel (Vessel of Nectar, outcome of the Sagar Manthan) from Asuras and handed over Amrita to Devas. Devas after drinking Amrita Nectar, become immortal and them were now more powerful than Asuras. Once again Devas were protected by Lord Vishnu.

Narasimha Avatar ~ Half Man – Half Lion

Lord Vishnu is Great Protect of His Devoted Devotees. Bhagat Prahalad (son of Asura Hiranyakashipu), is great devotee of Lord Vishnu since he was in womb of her mother. His father is great enemy and envious of Lord Vishnu. Hiranyakashipu after getting boon from Lord Brahma created havoc destruction on earth, declared himself as the most powerful God. Again to protect the dharma and devotees, Lord Vishnu incarnated Himself as Narsimha Avatar (Simha means Lion). Hiranyakashipu tried his level best to kill his own son Prahalad, but as Lord Vishnu protect his devotees, Prahalad always protected by the Lord Himself every time. Even Holika (sister of Hiranyakashipu) did not cause any harm to Prahalad (Holi festival celebrated in this regard). After getting tired from his son, Hiranyakashipu one day asked Prahalada to show him where is his Vishnu; so to protect his devotees from his Demon father, Lord Vishnu incarnated Himself as Narsimha (Half Lion ~ Half Man). Lord Narsimha killed the Hiranyakashipu by tearing his body parts by his Nails. This incarnation of Lord Vishnu is the manifestation of His diving anger, (if one do any harm to His unalloyed devoted devotees).
Note: Lord Vishnu took this appearance because, Hiranyakashipu had asked the Lord Brahma as boon, that no man, no animal, no weapon, etc can kill him. Lord Vishnu in Narsimha Avatar is (Half Man ~ Half Lion, used his Nails to kill the demon). Also there is great story after killing of Hiranyakashipu. No one in the entire cosmos pacifies the Lord Narsihma, except Prahalad such was His Divine Anger.)

Vaman Avatar ~ As a Dwarf

Lord Vishnu descended on earth to restore the authority of Indra over the heavens. Lord Vishnu was born of rishi Kashypa and mother Aditi. King Bali (grandson of Prahalad) was generous man who engaged in so many austerities and penances and had captured the entire three worlds. Bali symbolizes the Pride (Ahankar). Although he is great devotee of Lord, but he thought he can help anyone and can donate whatever one ask from him and eventually he forgot that there is Almighty above him. So one day while Bali was busy in performing Yagya, Lord Vishnu as Vaman ~ short Brahmin carrying wooden umbrella came to Bali and asked him three steps of land. To which Bali without any delay agreed, although he was warned by asura guru Shukracharya. Vaman showed His true identity enlarged Himself to gigantic form; he stepped from heaven to earth in first step, and from earth to netherworld with the second step. There was no place in entire cosmos for third step. To fulfill his promise Bali asked the Vaman to place third step over his head. Vaman placed his third step over Bali’s head. The Bali realized his mistake. Lord Vishnu in Vaman avatar regained the heaven for Indra. But being unbiased He gave immortality to Bali for his Humility and named Bali as Maha Bali.
Note: MahaBali is one of the 12 Mahajanas.
ParshuRama Avatar ~ Ram with Axe

Lord Vishnu took avatar as ParshuRama, and annihilated the Kshatriya (administrative class of society), who became ruthless, arrogant and exploited their subjects towards Brahmin (intelligent class of society). ParshuRama killed all Kshatriya kings twenty one times and donated the Earth to Brahmins. Althouth ParshuRama was born as Brahmin (to Jamadagni and Renuka) but he has unusual physical power, became better fighter then all Kshatriya. He belongs to Rishi Birghu Clan). He was student of Lord Shiva, who gave him the axe which ParshuRama always carry with him. Lord Shiva also taught him martial arts.
Kind Kartavirya, once went to Jamadagni's home and stole the Kamadhenu cow, which was supposed to give endless quantity of milk. Jamadgni was angered and brought Kamadhenu back after killing the king. On hearing this, sons of the king came back and killed Jamdagni. ParshuRama was angered (when he saw that his mother keep on hitting his chest 21 times at the corpse of Jamadagni, and he promised his mother Renuka that no Kshatriya will be alive now) and went and avenged the death of his father by killing all Kshatriya in 21 battles and showed the Supremacy of Brahmins over the Kshatriyas.
Note: ParshuRama is the founder of Kalaripayattu (One of the ancient form of Fighting System)
Note: ParshuRama is the Guru of Bhishma, Drona and Karan.
Note: ParshuRama is one of the Seven Chiranjivi (immortals).

Vyas Deva (Vedvyas) Avatar ~ Krishna Dvaipayana

Lord Vishnu took this Avtar, to compile all Sanatana Dharma Sacred Scriptures in written format. Vedvyas was born of Rishi Parashar and Satyavati. Vedvyas made the divisions of Vedas, and made extensions of its branches. He also wrote eighteen MahaPuranas, including Shrimad Bhagavatam. He dictated Mahabharata to Lord Ganesha, who penned down it, and hence authorship of Vedas, Puranas and Mahabharata, goes to Vyasdeva. Vyasdeva is great grandfather of Kaurav and Pandvas, and he is the father of Sukhdeva Goswami (another great ascetic Sage), who is the narrator of Srimad Bhagavad Puran to King Prakshit (grandchild of Arjuna).Note: VyasDeva is one of the Seven Chiranjivi (immortals)

Shri Rama Avatar

Lord Vishnu is second most famous incarnation, Maryada Prishotama Rama; Perfect Man or Lord of Self-Control or Lord of Virtue. His wife Sita is avatar of Mata Lakshmi and the embodiment of perfect womanhood. Lord Rama was born of King Dasrath and Koshaliya. Lord Rama is the hero of epic of Ramayana. He is more than just avatar. He is the Supreme Being descended on Mother Earth to get rid of all Demons (Asuars, Raskshash Clan headed by Kind Ravana). Lord Rama character shows what one need to do at the time of crisis, and keeping Morality the Highest issue of one’s life. The primary source of the life and journey of Rama is the epic Ramayana as composed by the Rishi Valmiki.

Shri BalRama Avatar

Note: BalRama is also regarded as incarnation of Adi Sheesh Nang.
BalRama was born as elder brother of Shri Krishna. BalRama and Shri Krishna both were brought up together from childhood. They both together killed Demons sent to Mathura by King Kansa (their maternal uncle). Balarama taught both Duryodhana and Bhima the art of fighting with a mace. During the Mahabharta ware BalRama remained neutral did not fight for anyone. He is also regarded as Haldar, the deity of Agriculture and Fertility.
Note: Vishnu then impregnated the womb of the Devaki with two parts of hair, one black, one white. To ensure their safety, their essence was transferred before birth to Rohini, who also desired a child. At birth, Krishna had a darker complexion, while Balarama was born fair. The other name of Balarama is also Sankarshana, meaning a spirit transferred between two wombs.

Shri Krishna Appearance ~ Summum Bonum Absolute Personality of Godhead

Precisely the Lord Himself appears on the Earth to fulfill His promise as mentioned (quoted) above from Bhagavad Gita. Shri Krishna is the Sac-Cit-Ananda Swaroop of Ishwar. He is the reciter of Bhagavad Gita. He is the Saarthi (Charioteer) of Arjuna in the Mahabharata War. He is slayer of Kansa (His maternal uncle), Sisupal (His Cousin), and many other demons. During infancy He killed Rakshas Putna. Shri Krishna is regarded as Leela Dhar, performed Raas Leela with Gopis of Brindavan (especially with Shrimati Radharani). Shri Krishna depicted Divine Dance on Kaaaliya Serpent. The major scriptures discussing Shri Krishna's life story are the Mahabharata (also Harivamsa), Shrimad Bhagavatam and Vishnu Puran.
Note: Shri Krishna's disappearance marks the end of Dvapara Yuga and the start of Kali Yuga (present age).

Buddha Avatar

Gautam Buddha (Enlightened One), was born as prince of Kapilavastu to King Suddhodhana and Maya. His original name was Siddhartha (Perfected Goal). After the disappearance of Shri Krishna, in Kali Yuga, true devotion to Vedas was replaced by empty rituals, so Lord Vishnu incarnated as Lord Buddha to rebuild the importance of Vedas with some modification for less intelligent people. Nobody was providing the satisfied answers to young Siddhartha questions regarding poverty, death, diseases etc. Then one day he kept everyone behind including his wife and child, and went to forest in the search of finding the Absolute Truth. When he came back he was full of Enlightenment, in state of Nirvana. The prime cause of all suffering is desire, one has to eradicate that, is one of the essence of Lord Buddha. 

Kalki Avatar

Note: I am not writing much on that, details can be found in Kalki Puran
The future (would be) incarnation of Lord Vishnu;  

Evolutionary Interpretation (Ref: Wikipedia)

The famous order of Dashavatar (Ten Incarnation) of Lord Vishnu symbolizes the modern theory of Human Evolution.

Matsya (fish): Satya Yuga
The first class of vertebrates; evolved in water

Kurma (turtle): Satya Yuga
Amphibious (living in both water and land)

Varaha (boar):  Satya Yuga
Wild Land Animal

Narasimha: Treta Yuga
(half lion ~ half human) emergence of human thoughts & intelligence in powerful wild nature)

Vamana (dwarf):  Treta Yuga
Short, Premature human beings

ParshuRama: Treta Yuga
Early Humans Living in forests & using weapons

Shri Rama: Treta Yuga
Humans living in community, beginning of civil society

Shri Krishna: Dwapara Yuga
Humans practicing Politics & Advanced societies

Buddha: Kali Yuga
Humans finding Enlightenment

Kalki: at the end of Kali Yuga
Advanced humans with great powers of destructions

Most Important Verses from Srimad Bhagavatam:

All of the above mentioned incarnations are either plenary portions or portions of the plenary portions of the Lord, but Lord Shri Krishna is the original Personality of Godhead. All of them appear on planets whenever there is a disturbance created by the atheists. The Lord incarnates to protect the theists.  (Srimad Bhagavatam Canto 1, Chapter 3, verses 28)

Whoever carefully recites the mysterious appearances of the Lord, with devotion in the morning and in the evening, gets relief form all miseries of life.  (Srimad Bhagavatam Canto 1, Chapter 3, verses 29)

Shrimad Bhagavatam (Canto 1 Chapter 3)