Krsna is likened to the original candle that lights all other candles of the same luminosity.

Furthermore, Krsna as His original Form has 64 qualities of which 4 of those are unique to only Kṛṣṇa.

No other Visnu-tattva expansion has those 4 extra qualities always in full like Kṛṣṇa does, although they are partially exhibited by some Visnu-tattva expansions like the one who plays the part of Krsna when Kṛṣṇa comes to the material world.

Krsna the Supreme Personality of Godhead and cause of all causes expands into innumerable categories of living entities however, as His Personal form, Krsna never leaves Vṛndāvana. 

Of those living entities, the ones who are almost equal to Krsna are called Visnu-tattva.

Others living entities like jiva-tattva (jiva-souls) are more independent from Krsna who each have their own unique personality separate from Krsna's Personality. 

Another living entity, Siva-tattva, is neither Visnu-tattva or jiva-tattva but is in a league of his own.

All are Krsna's expansions having a portion of Krsna's 64 qualities.

However, only Kṛṣṇa has all 64 qualities in full.

Visnu-tattva expansions have 60 of Krsna's 64 qualities which is 93.75% of Krsna's 100% attributes. 

Siva-tattva expansion has 55 of Krsna's 64 qualities which is 84.375% of Krsna's 100% attributes.

Jiva-tattva (jiva-soul) expansion has 50 of Krsna's 64 qualities which is 78.125% of Krsna's 100% attributes.

Being all-powerful Krsna can expand Himself into forms with the same power and characteristics He possesses, without diminishing Himself in anyway.

Although Krsna in His original Form has 64 qualities, 4 of those are unique to only Him because no other Visnu-tattva expansion has those 4 extra qualities all the time.

Krsna expands Himself to enjoy in a variety of ways through relationships with His innumerable devotees.

Some of His Visnu-tattva expansions manage the decaying impermanent material creation (Maha-Visnu, Garbhodakashayi Visnu, Paramatma) while others (Visnu/Narayana with many different names) manage the eternal blissful Vaikuntha planets. 

The jiva-tattva individual jiva-souls can choose to remain in the anti-material Spiritual Sky (Vaikuntha planets or Goloka-Vrindavana) or enter the temporary material creation because of having the quality of "free will."

As said above, Visnu-tattva expansions on the Vaikuntha planets are known as Lord Visnu, Lord Narayana and trillions of other names describing God's pastimes.

In the Vaikuntha planets, the relationship the jiva-souls have with Lord Visnu is all in-reverence, they see Visnu as the all powerful God and controller of everything.

Each Lord Viṣṇu on their spiritual planet, has a different name based on the pastimes going on in their particular Vaikuntha Planet.

In the Vaikuntha planets, there is a feeling of complete reverence and an attitude of deep respect with an overwhelming mood of awe and dedicated loving devotion to Visnu (God)

Unlike the jiva-souls in Goloka-Vrindavana who never see Krsna as God or even care, the jiva-souls in all the Vaikuntha planets always see Visnu/Narayana as the all worshipable Supreme Personality Lord or God.

However, Krsna in His original form remains aloof from the affairs of not only the material temporary decaying creation but also the perpetual Vaikuntha planets in the spiritual world.

This is because He is for ever enjoying loving pastimes with His friends, family, boy friends, girl friends and all other associates in Goloka-Vrindavana who Krsna sees are all equal to Him. 

And all jiva-souls in Goloka-Vrindavana see Krsna as the most amazing, caring, selfless Person they know, and love Him dearly but have no idea at all He is the Supreme Personality of Godhead and cause of all causes nor do they care. 

Amazingly no one in Goloka-Vrindavana sees Krsna as God the Supreme controller of all, He is just their best friend, parent, lover etc.

Krsna’s first Visnu-tattva expansion is Balarama, His elder brother in Goloka-Vrindavan, from Balarama comes all other Visnu-tattva expansions.

Although Krsna expands into many forms identical to Himself, He remains the one individual original independent entity who is simultaneously one and different with His spiritual worlds and material creation, meaning  all-pervasive and similtaneously a PERSON in Bodily Form.

Krsna also expands as Maha-Visnu (Karanodakshayi Visnu) who creates the material worlds which are actually the dreams of Maha-Visnu.

The material bodily vessels the jiva-soul's occupy by choosing to enter the temporary material creation, are from Maha-Visnu's dreams because the entire material creation are the dreams of Maha-Visnu according to Srimad Bhagavatam, every material bodily vessel in the material creation must be "hired" from Maha-Visnu.

Srila Prabhupada – "This material creation is the spirit soul’s dream. Actually all existence in the material world is a dream of Maha-Visnu, as the Brahma-Samhita describes-

"This material world is created by the dreaming of Maha-Visnu. The real, factual platform is the spiritual world, but when the spirit soul wants to imitate the Supreme Personality of Godhead, he is put into this dreamland of material creation." (SB Canto 4 Ch, 29.83)

This material creation is the spirit soul’s dream. Actually all existence in the material world is a dream of Maha-Visnu

Srila Prabhupada – "Everything happening within time, which consists of past, present and future, is merely a dream. This is the secret in understanding in all the Vedic literature." (SB Canto 4 Ch, 29.2b)

Srila Prabhupada – "Our contact with matter is just like dream. Actually we are not fallen. Therefore, because we are not fallen, at any moment we can revive our Krsna consciousness, we break the dream." (Tokyo Japan 1972, SB Canto 2 Ch, 9.1)

Srila Prabhupada – "Factually all of material existence is only a dream. Thus there is no question of past, present or future. Persons who are addicted to karma-kanda-vicara, which means ‘working for future happiness through fruitive activities’, are also dreaming. Similarly, past happiness and present happiness are merely dreams." (SB Canto 4 Ch, 29.2b)

Maha-Visnu is laying down sleeping and in that sleep, He dreams the material creation.

Everything past, present and future is eternally their in His dreams, and jiva-souls who choose to enter His material creation, live there in a material bodily vessel that comes from Maha-Visnu's dreams that are simultaneously the jiva-soul's desires (dreams) too.

Everything conceivable are in the dreams of Maha-Visnu that can for fill any material desire the jiva-souls have, everything there is comes from His dreams.

When Maha-Visnu dreams, He creates the material universe known as the Maha-tattva which is 25% of the spiritual sky or brahmajyoti.

Within that 25% of the spiritual sky we find billions of individual independent massive single universes called "Brahmandas"

Deep inside each Brahmanda universe, Maha-Visnu expands into a "secondary universe" as Garbhodakashayi Visnu.

And from Garbhodakashayi Visnu, a Lord Brahma appears in each "secondary material universe" and builds the many planetary systems.

This means there are billions of Garbhodakashayi Visnus and billions of Lord Brahmas but only one Maha-Visnu.

The size of each planetary system that exists in each material universe inside their Brahmanda, vary in size, some larger, some smaller than others.

In our material universe within our Brahmanda, we have 14 planetary systems and is considered a small universe.

Other universes inside their Brahmanda, have many more planetary systems.

The size of each Brahmanda and their inner universe depends on the how many heads their Lord Brahma has.

Some Lord Brahmas, like ours, has only 4 heads, while other Brahma's within their material universe may have 10, 20, 50, 500, 1000, 100,000 or even a million or more heads.

All inconceivable to the mundane mind.

All the billions of "Brahmanda universal shells coming from the Body of the sleeping Maha-Visnu as seen in painting below, have a secondary inner universe deep inside them with their own Garbhodakashayi Visnu and Lord Brahma.

Srimati Radharani and Krsna are eternally in their abode known as Goloka Vrindavana.

When Krsna wants to enjoy, He expands His potency or energy from within Himself that gives him enjoyment, that potency is also a PERSON like Krsna and Her name is Srimati Radharani.

Radharani is not a different person from Krsna, she is both one and different with Krsna. 

How could two people be one person or one person becomes two?

A simple example will illustrate how this is so, the sun cannot exist without the sunshine, nor the sunshine without the sun. We say, "the sun is in my room"—even though the sun itself is ninety-three million miles away—because the sun appears in the form of its energy.

Therefore the energy (the sunshine) and the energetic (the sun) are simultaneously one and different. 

Similarly, Radha and Krsna are simultaneously one and different. Krsna, the self-effulgent Lord, is the Supreme Personality of Godhead, and Srimati Radharani is His supreme pleasure energy.

Together They constitute the complete Absolute Truth.

Who is qualified to understand all discussed here?

One cannot understand anything about Radha and Krsna through mental speculation.

Krsna and His potencies are achintya, inconceivable, and ananta, unlimited. He is the very source of the mind itself, and therefore He is beyond the mind.

The limited mind cannot understand the unlimited Personality of Godhead. The Vedic literature explains this very logically- 

"That which is transcendental to material nature is inconceivable, whereas speculative arguments are all mundane. Since mundane arguments cannot touch transcendental subject matters, one should not try to understand transcendental subjects through mundane arguments."

When ordinary mundane intellectuals try to explain or interpret the identity or pastimes of Radha and Krsna, Krsna's unlimited nature bewilders them, and therefore they misconstrue everything.

Thus they sometimes consider Radha and Krsna to be like an ordinary boy and girl of the material world. But although they often pose as scholars, they do not know what they are talking about.

One should therefore strictly avoid the confused mundane ideas of such blundering intellectuals. 

If one wishes to understand Radha and Krsna, one must understand Them by hearing submissively from a bona fide authority, a genuine spiritual master. 

The original authority on Krsna is Krsna Himself. Everyone is first an authority regarding his own self, and this is also true regarding Krsna.

Moreover, since Krsna is unlimited, no one else can understand Him fully. Krsna's disciple Arjuna confirms this as follows in Bhagavad Gita As It Is -

svayam evatmanatmanam

vettha tvam purusottama

bhuta-bhavana bhutesa

deva-deva jagat pate

"Indeed, You alone know Yourself by Your own potencies, O origin of all, Lord of all beings, God of gods, O Supreme Person, Lord of the universe!" (BG, Ch 10.15)

Although Krsna is inconceivable to mental speculation, those to whom He reveals Himself can understand Him. Krsna first gave such transcendental knowledge to Brahma, the first created living being.

Brahma later transmitted this knowledge to his son Narada, who transmitted it to Vyasa, the author of Bhagavad Gita As It Is. 

In this way, the knowledge has descended from master to disciple, through a chain of the Bhakti tradition, down to the present day.

A spiritual master in this disciplic line is a bona fide authority regarding Krsna. He is the proper person from whom to receive transcendental knowledge.

What pleases Krsna?

According to Srila Prabhupada, Krsna is the reservoir of all pleasure, and therefore He is all-attractive. Yet Krsna Himself derives pleasure from the service rendered by His devotees.

Such devotional service attracts even Him. 

Krsna Himself, while speaking to a friend, confirms this as follows in Srimad Bhagavatam-

Krsna - "My dear Uddhava, you may know from Me that the attraction I feel for devotional service rendered by My devotees is not to be equaled even if one performs mystic yoga, philosophical speculation or ritualistic sacrifices, studies Vedanta, practices severe austerities or gives up everything in charity. These are, of course, very nice activities, but they are not as attractive to Me as the transcendental loving service rendered by My devotees." (SB Canto 11, Ch 12 Text 1)

Krsna is full in six opulence's - 

beauty, 

wealth, 

fame, 

strength, 

knowledge,  

renunciation. 

No amount of material opulence, therefore, can attract Him. Just as one could not attract a millionaire by offering him a few dollars, one cannot attract Krsna merely by one's limited material opulence. 

Nevertheless, pure devotional service attracts even Krsna. This is the unique transcendental excellence of devotional service.

Srimati Radharani is the embodiment of pure devotional service. No one can be a greater devotee than She. 

The very name Radharani comes from the Sanskrit word aradhana, which means worship. Her name is Radharani because She excels all in worshiping Krsna.

Although Krsna is so beautiful that He can attract millions of Cupids and is therefore called Madana-mohana, "the attractor of Cupid," Radharani can attract even Krsna! 

She is therefore called Madana-mohana-mohini—"the attractor of the attractor of Cupid."

The same Krsna who is not attracted by any amount of material opulence finds Srimati Radharani irresistible. 

One time Krsna, to joke with the gopis, the cowherd girls of Vrndavana, was hiding Himself beneath a bush, but finally they spotted Him from a distance. 

Krsna then changed Himself into His four-armed form of Narayana. When the gopis approached and found Narayana instead of Kṛṣṇa, they were not very interested in Him; only Krsna's original two-armed form attracted them.

They therefore offered their respectful obeisance's unto Lord Narayana and prayed that He would bestow upon them the benediction of Krsna's eternal association. Then they went on searching for Krsna.

When Srimati Radharani passed by, however, Krsna tried to maintain His disguise as Narayana but was unable to do so; he kept slipping back into His original two-armed form. This illustrates the great influence of Srimati Radharani's pure transcendental love.

Krsna says in Bhagavad Gita As It Is that as one surrenders unto Him, He reciprocates accordingly. 

Therefore the more Radharani tries to please Krsna, the more He desires to please Her, thus in turn increasing Her enthusiasm to increase His pleasure.

Therefore although the Lord is unlimited, both He Himself and His pleasure potency are always increasing. 

The all-blissful reciprocation between the Lord and His pleasure potency is expressed in the transcendental pastimes of Radha and Krsna, which are described in detail in "KRSNA BOOK, the Supreme Personality of Godhead." by His Divine Grace A.C. Bhaktivedanta Swami Prabhupada.

The reciprocation of loving exchanges between Radha and Krsna and all marginal living entities is the essence of spiritual love.

In the spiritual world, love between Krsna, and among all His pure devotees is based on selfless loving reciprocal exchanges of service, voluntary personal offerings to Krsna that are unique to each individual devotee.

Such loving co-operation and selfless devotion among devotees, brings out the very best and full potential of each devotee's spiritual personality and unique character.

In this way, the pure devotees are always trying to please beautiful Krsna in so many ways in service and in playful sport in the mood of Krsna Consciousness.

And Krsna is so kind He always reciprocates in so many amazing ways more than one can ever realize.

All the devotees serve Krsna selflessly and unconditionally in their own unique way in the mood of loving co-operation without any desire for personal gain.

Srila Prabhupada - "Love is reciprocal, voluntary, good exchange of feeling. Then there is love. Not by force! Krsna does not want to become a lover like that, ‘You love me, otherwise I shall kill you!" (Washington DC July 8, 1976)

Srila Prabhupada - ''Because you are Son of God you have acquired the quality of your father. You have got little independence. So God does not interfere with your little independence. If you persist to go off and enjoy independently then God says, "All right, you can go." (Melb, Australia June 25, 1974).*^*.

From Matchless Wondergifts.