Lord Krishna is the Supreme Personality of Godhead. He is the source of all other incarnations and forms of God. He is the ultimate and end of all Truth and philosophical enquiry, the goal or end result of Vedanta. He is the all-attractive personality and source of all pleasure for which we are always hankering. He is the origin from which everything else manifests. He is the unlimited source of all power, wealth, fame, beauty, wisdom, and renunciation. Thus, no one is greater than Him. Since Krishna is the source of all living beings, He is also considered the Supreme Father and source of all worlds. He is shown with a blue or blackish complexion. This represents absolute, pure consciousness, which also is unconditional love. Krishna is the embodiment of love. He is also sat-chit-ananda vigraha, which means the form of eternal knowledge and bliss, for which we are all seeking.
The reason why the Lord is called “Krishna” is explained in a book known as the Sri Caitanya Upanishad, which is connected with the Atharva-veda. In verse twelve it is explained: “These three names of the Supreme Lord (Hari, Krishna and Rama) may be explained in the following way: (1) ‘Hari’ means ‘He who unties [harati] the knot of material desire in the hearts of the living entities’; (2) ‘Krishna’ is divided into two syllables ‘krish’ and ‘na’. ‘Krish’ means ‘He who attracts the minds of all living entities’, and ‘na’ means ‘the supreme transcendental pleasure’. These two syllables combine to become the name ‘Krishna’; and (3) ‘Rama’ means ‘He who delights [ramayati] all living entities’, and it also means ‘He who is full of transcendental bliss’. The maha-mantra (Hare Krishna Hare Krishna Krishna Krishna Hare Hare Hare Rama Hare Rama Rama Rama Hare Hare) consists of the repetition of these names of the Supreme Lord. In this way, Krishna’s names represent His character and qualities, which, in this case, means the greatest and all attractive transcendental pleasure.