Krsna is the Supreme Personality of Godhead and cause of all causes meaning everything comes from Kṛṣṇa.

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

Srila Prabhupada - "Although there are many expansions, Lord Śrī Kṛṣṇa is the origin, as confirmed in the Brahma-saṁhitā. He is like the original candle, from which many thousands and millions of candles are lit. Although any number of candles can be lit, the original candle still retains its identity as the origin. In this way Kṛṣṇa expands Himself into so many forms, and all these expansions are called viṣṇu-tattva. Viṣṇu is a large light, and we are small lights, but all are expansions of Kṛṣṇa." (CC Introduction)

Srila Prabhupada - "The original Lord Kṛṣṇa never leaves Goloka Vṛndāvana. All the plenary expansions are one and the same Viṣṇu-tattva, and there is no difference in Their potency." (SB, Canto 3 Ch 1 Text 34 Purport)

Krsna is the source of all Narayana/Visnu expansions of God, who all originated (expanded) from Krsna in Goloka-Vrindavana.

Each Visnu/Narayana Form further have their own perpetual Vaikuntha planet where they reside as a four armed Form whose Vaikuntha planets surround Krsna's central Abode of Goloka-Vrindavana. 

Together the the Vaikuntha planets and Goloka Vrindavana take up 75% of the Spiritual Sky where everything there is living as individual forms, lifeless material energy or Maya does not exist there in the Vaikuntha planets or Goloka-Vrindavana.  

The other 25% of the Spiritual Sky is the temporary (decomposing) material world where the visiting individual jiva-souls from the spiritual world, must acquire a material bodily container or vessel to enter the material creation.

Srila Prabhupada - "We are not the owner of this material body, not the owner of the material 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)

All the material bodily vessels in the material world belong to Maha-Visnu and must be aquired from Him in order to enter the material world.

However, all such material bodily vessels are temporary and subject to constant decline, decay and always in need of constant maintenance, nothing made of matter lasts forever in the material world, everything is always in a constant state of decomposition.

This causes the eternal individual jiva-souls within those material bodies, who are visiting from the spiritual worlds as passengers in those bodily vessels, to continue taking birth after birth in the material world and continue trying to satisfy their desires and material senses.

The temporary material world is created and maintained by Krsna's expansion's 

1 - Karanarnavasayi Visnu (Maha-Visnu), who creates all the unlimited massive Brahmanda universes. 

2 - Garbhodakashayi Visnu (Hiraņyagarbha) who creates a "secondary material universe" inside the massive surrounding Brahmanda universe.

3 - Ksirodakasayi Visnu (Paramatma or Super Soul) who resides next to every marginal living entity (jiva-soul) within what ever material bodily vessel they take out of the 8 million 400 species of material life.

Srila Prabhupada - "For material creation, Krsna's plenary expansion assumes three Visnus. The first, Mahā Viṣṇu, creates the total material energy, known as the mahat-tattva. The second, Garbhodakaśāyī Viṣṇu, enters into all the universes to create diversities and the third, Kṣīrodakaśāyī Visnu, is diffused as the all-pervading super soul in all the universes; in the heart of every living being, is known as Paramātmā. He is present even within the atoms.The goal of life is to know Kṛṣṇa, who is situated within the heart of every living being as Paramātmā, the four-handed Viṣṇu form." (BG, Ch 7 text 4 Purport)

There is only one Maha-Visnu, but unlimited Garbhodakashayi Visnus and Ksirodakasayi Visnus.

This is because of the unlimited number of "secondary universes" there are, that are each deep within their massive Brahmanda universe.

Krsna is the original source of Maha-Visnu who creates these material universes (Brahmandas) that originate from Maha-Visnu's breathing and the pores of His skin as seen in photo below.

As said above, deep inside each Brahmanda material universe, there is a "secondary inner" enclosed universe where Maha-Visnu expands as Garbhodakashayi Visnu, from whom Lord Brahma appears at the top of a lotus flower growing from the naval of Garbhodakashayi Visnu and builds the many planetary systems in his material universe. 

There are unlimited Brahmanda universes, each having a secondary material universe inside of them meaning each has their own Garbhodakashayi Visnu and Lord Brahma.

In these "secondary material universes" created by Garbhodakashayi Visnu deep within each Brahmanda universe, Lord Brahma builds the planetary systems.

In our secondary material universe, there are 14 planetary systems.

In other material universes inside their Brahmanda, they have many more planetary systems than just 14.

Our material universe is one of the smallest.

The size of each Brahmanda and inner universe depends on how many heads Lord Brahma has, in our material universe he has four heads, while in other material universes Brahma may have 10, 20, 50, 100, 100,000, one million or 10 million. The workings of this material universe is beyond our comprehension.×. ×..