KrishnaKrishna pronunciation (help·info) (Sanskrit: कृष्ण Kṛṣṇa in IAST, pronounced [ˈkr̩ʂɳə]), literally "black, dark blue" is the eighth avatar of Vedic Supreme God Vishnu in Hinduism. The word Krishna means one with dark complexion and one who attracts all. The name Krishna appears as the 57th and 550th name of Lord Vishnu in Vishnu Sahasranama of Mahabharata. The name Krishna is also amongst the 24 Keshava Namas of Lord Vishnu which are recited and praised at the beginning of all Vedic pujas in Hinduism.
Bhagavata Purana depicts Lord Brahma with all the gods (devas) offering the hymns of Purusha sukta at the shore of Ksheera Sagara (the ocean of milk), to Lord Vishnu requesting him to appear and advise to the solution for the calamities and atrocities being tolerated by Bhumi (Goddess Earth) due to huge number of demoniac kings prevailing on planet earth in that time, agreeing to which, Lord Vishnu incarnated as Krishna[
According to Bhagavata Purana, which is a sattva purana, Lord Krishna is termed as Svayam Bhagavan since he was the purna-avatara or full incarnation of Supreme Lord Vishnu. As stated in Bhagavata Purana, Lord Vishnu or Narayana appeared before Vasudeva and Devaki in his divine real form before taking birth. Both Vasudev and Devaki after praising Lord Vishnu requested him to hide his divine form agreeing to which Lord Vishnu transformed himself into a small human baby. According to this account, Lord Krishna never took birth from the womb of his mother like a common human baby and was himself Lord Narayana or Vishnu who came down to Earth from his Supreme Abode Vaikuntha to eradicate the evil forces, to restore the Dharma and to liberate the worthy ones or devotees and had the appearance of a normal human being. 
Krishna is often described and portrayed as an infant or young boy playing a flute as in the Bhagavata Purana, or as a youthful prince giving direction and guidance as in the Bhagavad Gita. The stories of Krishna appear across a broad spectrum of Hindu philosophical and theological traditions. They portray him in various perspectives: a god-child, a prankster, a model lover, a divine hero and the Supreme Being. The principal scriptures discussing Krishna's story are the Mahabharata, the Harivamsa, the Bhagavata Purana, and the Vishnu Purana.
Krishna is easily recognized by his representations. Though his skin colour may be depicted as black or dark in some representations, particularly in murtis, in other images such as modern pictorial representations, Krishna is usually shown with blue skin. He is often shown wearing a yellow silk dhoti and peacock feather crown. Common depictions show him as a little boy, or as a young man in a characteristic relaxed pose, playing the flute. In this form, he usually stands with one leg bent in front of the other and raises a flute to his lips, known as Tribhangi Mudra, accompanied by cows, emphasizing his position as the divine herdsman, Govinda, or with the gopis (milkmaids) i.e. Gopikrishna, stealing butter from neighbouring houses i.e. Navneet Chora or Gokulakrishna, defeating the vicious serpent i.e. Kaliya Damana Krishna, lifting the hill i.e. Giridhara Krishna ..so on and so forth from his childhood / youth events.Worship of a deity of Krishna, either in the form of Vasudeva, Bala Krishna or Gopala, can be traced to as early as 4th century BC. Worship of Krishna as svayam bhagavan, or the Supreme Being, known as Krishnaism, arose in the Middle Ages in the context of the bhakti movement. From the 10th century AD, Krishna became a favourite subject in performing arts and regional traditions of devotion developed for forms of Krishna such as Jagannatha in Odisha, Vithoba in Maharashtra and Shrinathji in Rajasthan. Since the 1960s the worship of Krishna has also spread in the West, largely due to the International Society for Krishna Consciousness.