Krsna is the Supreme Personality of Godhead and cause of ALL causes.

Krsna expands Himself as innumerable categories of living entities known as-

1 - Visnu-tattva (full expansions of Krsna), 

2 - Sakti-tattva (internal intimate potency expansions of Kṛṣṇa)

3 - Siva-tattva, mysterious independent expansion of Krsna who is not Visnu-tattva or jiva-tattva. 

4 - Jiva-tattva [jiva-souls] "separated expansions" with their own individuality and unique independent personality who can accept or reject Krsna if they choose and therefore called "marginal living entities."

Krsna is likened to the original candle who lights all other candles (Visnu-tattva full expansions) of the same luminosity. 

Furthermore, Krsna as His original Vrindavana Form has 64 qualities of which 4 of those are unique to only Kṛṣṇa all the time, and He never leaves Vṛndāvana.

Krsna’s first Visnu-tattva expansion is Balarama and from Him, all other Visnu-tattva expansions manifest and represents Kṛṣṇa outside Vrindavana in the Vaikuntha planets, and material world.

No Visnu-tattva expansion has those 4 extra qualities always like Kṛṣṇa does, they only can always manifest 60 of Krsna's 64 qualities all the time which is having 93.75% of Krsna's attributes.

Krsna is the Supreme Personality of Godhead and cause of all causes and expands as innumerable categories of different living entities known as Visnu-tattva, sakti-tattva, Siva-tattva and jiva-tattva. 

Krsna’s first expansion is Balarama and from Him all other Visnu-tattva expansions for both the Vaikuntha planets and the material world manifest.

Those "living entities" who are almost equal to Krsna are called "Visnu-tattva and Visnu-"sakti"-tattva."

Others "living entities" like the individual jiva-tattva (jiva-souls) are more independent from Krsna and have their own unique personality and an independent character separate from Krsna's Personality. 

This means the jiva-souls have free will that even allows them to accept or reject Krsna. Therefore jiva-souls are called the "marginal living entities" because they can live in either the spiritual world or the material world due to their free will. 

Another living entity category, Siva-tattva (Siva), is neither Visnu-tattva or jiva-tattva but is in a league of his own with 85.938% of Krsna'squalities which is having 55 of Krsna's 64 qualities. 

All the variety of living entities are Krsna's expansions, each having a portion of Krsna's 64 qualities however, only Kṛṣṇa has all 64 qualities in full (100%).

Visnu-tattva and Visnu-"sakti"-tattva expansions have 60 of Krsna's 64 qualities, which is 93.75% of His 100% attributes. 

Siva-tattva expansion have 55 of Krsna's 64 qualities, which is 85.938% of Krsna's 100% attributes.

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

Being all-powerful, Krsna can expand Himself into unlimited 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.

Krsna's Visnu-tattva expansions manage the decaying impermanent material creation such as Maha-Visnu, Garbhodakashayi Visnu, and  Paramatma (Supersoul). 

All Visnu/Narayana Forms have unlimited different names who are all the Supreme Personality of Godhead also. They each live on their own eternal blissful Vaikuntha planet living in different roles (pastimes)

Visnu-tattva expansions also enter the material world under unlimited different names like Maha-Visnu, Garbhodakashayi Visnu, Paramatma, Narsingadeva, Ramachandra, Varaha etc. 

The individual eternal jiva-souls can choose to remain in the "anti-material" Spiritual Sky (Vaikuntha planets or Goloka-Vrindavana), or enter the temporary "material creation" because they have "free will" as part of their "eternal" constitutional make-up.

The individual marginal living entities (jiva-souls) were never created, they are eternal without beginning or end just like Krsna.

Just like the "sun-rays" exist simultaneously with the "Sun-disc," Similarly, the jiva-souls have always existed for infinity like Krsna has. Just like Krsna, the jiva-souls are beginningless and endless meaning they were NEVER created.

The jiva-souls are eternal spiritual living PERSONS and can never be destroyed, terminated or extinguished, the jiva-souls are indestructible.

Bhagavad Gita As It Is - “Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be.” (BG, Ch 2 text 12, 1983 edition)

Bhagavad Gita As It Is - "As the embodied soul continuously passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. A sober person is not bewildered by such a change." (BG, Ch 2 text 13)

Bhagavad Gita As It Is - “Those who are seers of the truth have concluded that of the nonexistent [the material body] there is no endurance and of the eternal [the soul] there is no change. This they have concluded by studying the nature of both." (BG, Ch 2 text 16)

Bhagavad Gita As It Is - “That which pervades the entire body you should know to be indestructible. No one is able to destroy that imperishable soul." (BG, Ch 2 text 17)

Bhagavad Gita As It Is - “Neither he who thinks the living entity the slayer nor he who thinks it slain is in knowledge, for the self slays not nor is slain." (BG, Ch 2 text 19)

Bhagavad Gita As It Is - "For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain." (BG Ch 2 text 20 "corrected" 1983 edition)

Bhagavad Gita As It Is - "O Pārtha, how can a person who knows that the soul is indestructible, eternal, unborn and immutable kill anyone or cause anyone to kill?" (BG, Ch 2 text 21)

Bhagavad Gita As It Is - "As a person puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up the old and useless ones." (BG, Ch 2 text 22)

Bhagavad Gita As It Is - "The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind." (BG, Ch 2 text 23)

Bhagavad Gita As It Is - "This individual soul is unbreakable and insoluble, and can be neither burned nor dried. He is everlasting, present everywhere, unchangeable, immovable and eternally the same." (BG, Ch 2 text 24)

Bhagavad Gita As It Is - "It is said that the soul is invisible, inconceivable and immutable. Knowing this, you should not grieve for the material body." (BG, Ch 2 text 25)

Bhagavad Gita As It Is - "One who has taken his birth is sure to die, and after death one is sure to take birth again. Therefore, in the unavoidable discharge of your duty, you should not lament." (BG, Ch 2 text 27)

Bhagavad Gita As It Is - "Some look on the soul as amazing, some describe him as amazing, and some hear of him as amazing, while others, even after hearing about him, cannot understand him at all." (BG, Ch 2 text 29)

Bhagavad Gita As It Is - "O descendant of Bharata, he who dwells in the material body can never be slain. Therefore, you need not grieve for any living being." (BG, Ch 2 text 30)

Srila Prabhupada – "There are no new souls, new and old are due to this material body, but the jiva-soul is never born and never dies, so if there is no birth, how can there be new souls?" (Letter to Jagadisa dasa, 9 July 1970)

As said above, Visnu-tattva expansions on the Vaikuntha planets are known as Lord Visnu, and Lord Narayana and trillions of other names that describes their particular pastimes.

On the Vaikuntha planets the jiva-souls have an all-in-reverence relationship with Lord Visnu, those who voluntarily choose to go there see Lord Visnu as the all powerful God and controller of everything.

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

On the Vaikuntha planets, there is complete reverence and deep respect and humility with an overwhelming mood of awe and dedicated in their love for Lord Visnu (God)

Unlike the jiva-souls in Goloka-Vrindavana who never see Krsna as God or even care, the jiva-souls on 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 that surround His personal abode of Goloka-Vrindavan.

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

The jiva-souls in Goloka-Vrindavana see Krsna as the most amazing, caring, selfless "Person" they know, and love Him dearly, but have no idea 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 things, He is just their best wonderful friend, parent, lover etc they feel safe to be with and always remember.

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

Srila Prabhupada - "Balarāma executes the orders of Lord Kṛṣṇa in the work of creation, and in the form of Lord Śeṣa He serves Kṛṣṇa in various ways. According to expert opinion, Balarāma, as the chief of the original quadruple forms, is also the original Saṅkarṣaṇa. 

Krsna's first expansion Balarāma expands Himself in five forms-

(1) Mahā-saṅkarṣaṇa, 

(2) Kāraṇodakaśāyī, 

(3) Garbhodakaśāyī, 

(4) Kṣīrodakaśāyī, 

(5) Śeṣa. 

These five plenary portions are responsible for both the spiritual and material cosmic manifestations. In these five forms Lord Balarāma assists Lord Kṛṣṇa in His activities. The first four of these forms are responsible for the cosmic manifestations, whereas Śeṣa is responsible for personal service to the Lord. 

Śeṣa is called Ananta, or unlimited, because He assists the Personality of Godhead in His unlimited expansions by performing an unlimited variety of services. Śrī Balarāma is the servitor Godhead who serves Lord Kṛṣṇa in all affairs of existence and knowledge. Lord Nityānanda Prabhu, who is the same servitor Godhead, Balarāma, performs the same service to Lord Gaurāṅga by constant association." (CC Adi 5.10, Translation and Purport)

Srila Prabhupāda - "Lord Nityānanda is Balarāma, who is the origin of Mahā-Viṣṇu. Kṛṣṇa’s first expansion is Balarāma, a portion of whom is manifested as Saṅkarṣaṇa, who then expands as Pradyumna. In this way so many expansions take place." (CC Introduction)

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 eventually expands as Maha-Visnu (Karanodakshayi Visnu) and creates the material world which are actually the dreams of His expansion Maha-Visnu.

The material bodily vessels the jiva-souls possess when they choose to enter the temporary material creation, are chosen from the dreams of Maha-Visnu.

The material creation takes up 1/4 of the Spiritual Sky, everything going on within the unlimited Brahmanda universes existing there, are the dreams of Maha-Visnu according to Srimad Bhagavatam.

Every bodily material vessel in the material world must be first "hired" from Maha-Visnu the owner of all material bodily vessels and their surroundings.

Srila Prabhupada - "We are not the owner of this body, not the owner of the senses. The senses are "hired" from the Supreme Lord. This is very subtle understanding, one should know the proprietor of the senses is God." (March 1966 New York City USA)

Srila Prabhupada - "The "immediate" expansions of the Lord are called svāṁśa or "personal direct" expansions (Visnu-tattva). The "separated" expansions of the Lord are called vibhinnāṁśa - jiva-tattva or independent jiva-souls like us." (BG, Ch 10 text 37, Purport)

Each individual jiva-soul in the spiritual world can "choose" to "voluntarily" serve Krsna in an unlimited variety of ways as an unlimited varieties of bodily forms, or even reject Krsna if they choose to do so, and enter or return to the impermanent material world. 

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 text 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 text 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 text 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 text 2b)

Maha-Visnu is laying down sleeping and in that sleep He dreams the entire material creation of unlimited Brahmanda universes with ever conceivable out come, coving anything the jiva-souls desire.

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 temporary material universe known as the Maha-tattva, which takes up 25% of the spiritual sky or brahmajyoti.

Within that 25% of the spiritual sky, we find an unlimited number of massive universes called "Brahmandas." 

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

And from those Garbhodakashayi Visnus within each of their secondary universes, an unlimited number of Lord Brahmas appear and builds the many planetary systems within their material universe.

This means there are unlimited Garbhodakashayi Visnus and and an unlimited number of Lord Brahmas however, there is only one Maha-Visnu.

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

In our material universe deep inside our Brahmanda, we have 14 planetary systems and is considered a small universe. Other material universes inside their Brahmanda, have many more planetary systems.

The size of each Brahmanda and their inner universe inside it, 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 universes 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 and experience loving exchanges with a women, He expands His potency or energy from within Himself that gives Him enjoyment. This potency He expands as is a PERSON in the form of a woman and Her name is Srimati Radharani.

Radharani is not a different person from Krsna, or, rather, she is both one with and different from Him. How could two people be one person or one person be 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 

"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 text 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- 

Srimad Bhagavatam - "Krsna says, "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." 

One time Krsna, to play a joke on the gopis or cowherd girls of Vrndavana, was hiding 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).**.