"Sakti" means different categories of Krsna's "energies."

Sakti-tattva referes to all of Krsna's energies however, there are different categories of living and non-living sakti. 

For example, the Visnu-"sakti"-tattva living entities are a category of Visnu-tattva expansions, who are "Krsna" playing multiple roles in His own pastimes. And so are Visnu/Narayana on the Vaikuntha planets in the spiritual world.

Then you have Visnu-tattva expansions of Maha-Visnu, Garbhodakashayi Visnu and Paramatma (Supersoul) managing the material world.

Also, the material energy (mahat-tattva) is the sakti of Kṛṣṇa 

Sakti can also refere to the marginal living entities (jiva-souls) like us who are independent expansions of Krsna endowed with free will in the spiritual world and have their own individuality, unique personality and a separate identity from Krsna.

Srila Prabhupada - "Tattva is manifested in different ways

1 - Viṣṇu-tattva, 

2 - Viṣṇu-"śakti"-tattva,

3 - jīva-tattva, like that." (Lecture SB, Canto 6 Ch 2 Text 7, Vrndavana, Sep 10, 1975)

As said above, "sakti" is the different categories of Krsna's energies, the living entities and non-living (matter) as Srila Prabhupada explains. 

Srila Prabhupāda - "Sakti means “energy.” There are many types of energies of the Supreme Lord, and all of them are auspicious. Brahmā, Viṣṇu and Maheśvara are called guṇa-avatāras, or incarnations of material qualities. In the material world we compare these different incarnations from different angles of vision, but since all of them are expansions of the supreme auspicious, all of them are auspicious, although sometimes we consider one quality of nature to be higher or lower than another. The mode of ignorance, or tamo-guṇa, is considered very much lower than the others, but in the higher sense it is also auspicious. The example may be given herein that the government has both an educational department and criminal department. An outsider may consider the criminal department inauspicious, but from the government’s point of view it is as important as the education department, and therefore the government finances both departments equally, without discrimination." (SB Canto 4 Ch 6 text 43 Purport)

Within Puranic literatures and general Vaiśnava philosophy the word tattva is often used to denote certain categories or types of being or energies such as-

Kṛṣṇa-tattva.

The Supreme personality of Godhead and cause of ALL causes. Meaning the causative factor of everything including other Tattvas.

Viśnu-tattva.

Any incarnation or direct expansion of Śrī Kṛṣṇa who have 93.75% of Krsna's qualities, which means they have 60 of Krsna's 64 qualities.

Śakti-Tattva. 

The multifarious energies of Śrī Kṛṣṇa. It includes his internal potency, Yoga Maya and prakṛti (material energy)

Yogamaya.

Yogamāyā means that which connects you. Yogamāyā, the original yogamāyā, is Kṛṣṇa's internal potency who is Srimati Rādhārāṇī.

Jiva-tattva (jiva-souls)

The individual marginal living entities (jiva-souls) who have 78.125% of Krsna's qualities, which means they have 50 of Krsna's 64 qualities.

Srimati Radharani is the internal energy, we are marginal energy (jiva-souls)

Srila Prabhupada - "Regarding your question about our relationship with Srimati Radharani, She is the internal energy, we are marginal energy (jiva-souls). Marginal means sometimes internal, sometimes external. When we are under the internal energy, that is our normal life, and when we are under the external energy, that is our abnormal life. Therefore, we are called marginal energy (jiva-souls); we can be either this way or that way. But being qualitatively one with the purusa, our tendency is to remain in the internal energy. Being in the external energy is our artificial attempt." (Letter to Lilavati, Allston, Mass, USA 25 April, 1969)

Śiva-tattva (Lord Siva)

Śiva is not considered to be jiva-tattva or Visnu-tattva, and is in a league of his own who has 85.938% of Krsna's qualities, which is having 55 of Krsna's 64 qualities.

Mahat-tattva.

The total material energy (prakṛti)

Devotee - "In the material world, we are bound by māyā, mahā-māyā. In the spiritual world, is there another relationship with yogamāyā?"

Srila Prabhupāda - "Yes, Yogamāyā"

Devotee - "Could you explain a little bit about that?"

Srila Prabhupāda - "Yogamāyā means it is Kṛṣṇa's exhibition of māyā, but maya in the material world it is temporary. In the spiritual world, that is also exhibition of Kṛṣṇa's māyā, but it is permanent. Here in the material world mahamaya is also a perverted reflection, we say. 

Just like a shadow, the shadow of the tree in the water, everything is perverted, opposite. So that shadow is not the substance. The substance is there. On the bank of the river, that is reality. Similarly the spiritual world is there also, everything is there. There are trees, there are fruits, there are flowers, there are men—everything is there, birds, beasts, everything. But they are all real and permanent. 

Here, bahu-rūpa. Bahu-rūpa means, "it is not reality." That, this bahu-rūpa is also reflection, but it is not real. That is the difference. Ivābhāti, therefore it is called ivābhāti - It appears like that, actually it is not." (Lecture SB, Canto 2 Ch 9 Text 2, Melb, Australia April 4, 1972)

Tamāla Kṛṣṇa - "Srila Prabhupada the devotees want to know how we may recognize yogamāyā, how we may know."

Srila Prabhupāda - "Yogamāyā? Yogamāyā means that which connects you. Yoga means connection. 

1 - Yogamaya - When you gradually advancing in Kṛṣṇa consciousness, that is the action of yogamāyā. 

2 - Mahamaya - When you are gradually forgetting Kṛṣṇa, that is the action of mahāmāyā. 

Māyā is acting upon you. The one is dragging you down (Mahamaya), and one is pushing or dragging you up (Yogamāyā) So, just like the example, that you are always under the laws of government. You cannot deny. If you say, "I don't agree to abide by the laws of government," that is not possible. But when you are a criminal, you are under the police laws, and when you are gentleman, you are under the civil laws. 

The laws are there. In any situation, you have to obey the laws of government. If you remain as a civilized citizen, then you are always protected by the civil law. But as soon as you are against the state, the criminal law will act upon you. So the criminal activities of law is mahāmāyā, threefold miseries, always. Always putting in some sort of misery. And the civil department of Kṛṣṇa, ānandāmbudhi vardhanam. You simply go on increasing the, I mean to say, depth of the ocean of joy.

Ānandambudhi-vardhana. That is the difference, yogamāyā and mahāmāyā. The original yogamāyā is Kṛṣṇa's internal potency. That is Rādhārāṇī." (Seattle, USA Oct 18, 1968)

Srila Prabhupada - "Regarding your questions-

Question 1 - "Are great sages put under yogamaya or maya?"

Question 2 - "Are all the eternally liberated souls under yogamaya?" 

Answer, 1 - Yogamaya means the mercy of the Supreme Lord which connects a devotee in the transcendental loving service of the Lord.

Answer, 2 - Mahamaya means the external potency of the Lord which puts a conditioned jiva-soul into illusion that he will be happy by material adjustment. So great sages who are impersonalists are also under the spell of mahamaya, because a conditioned jiva-soul in the material world wants to improve his material position as exalted as possible, and the concept of becoming one with the Supreme Lord is the greatest illusion for them. 

Because it is a fact that nobody can be equal or greater than the Supreme Personality of Godhead, and as such, anyone desiring to become one with the Supreme means that he is still in the trap of maya. On the other hand, a humble devotee who may not be a great sage, but simply by his implicit acceptance of the Lotus Feet of the Lord as the goal of his life means that he is under the protection of yogamaya." (Letter to Aniruddha, Los Angeles 14 Nov, 1968)

Loving devotional service to Krsna is ALWAYS based on a "two-way" voluntary exchange of personal feelings, manifesting in "simplistic" loving acts of reciprocation between Krsna and His devotees, where His devotees voluntarily contribute their own unique expressions (offerings) of devotion to Him. 

This is the real meaning of surrendering to Krsna's will that NEVER denies the "free will" (freedom of individual expression) of each jiva-soul.

So there are different categories of sakti-tattva among the category of "living entities."

So yes, we are the jiva-tattva souls known as the marginal living entities who have our own independence and free will, yet simultaneously ALWAYS dependent on Visnu in Vaikuntha and Krsna in Goloka-Vrindavana, or Maha-Visnu in the material creation.

While other living entities are more direct expansions of Krsna called Visnu-tattva and Visnu-sakti-tattva expansions.

Then there is Siva-tattva who is neither a jiva-tattva soul, Visnu-tattva or Visnu-sakti-tattva. As said above, Lord Siva is in a league of his own.

The Visnu-sakti-tattva and Visnu-tattva expansions are Krsna playing another role in His own pastimes, whereas the jiva-tattvas are independent thinking living entities endowed with free will in the spiritual worlds who have their own personality, sense of self and unique individuality as explained above.

The majority, over 90%, of jiva-souls are perpetually situated in either Vaikuntha or Goloka-Vrindavana and choose to NEVER fall down to the material mundane temporary creation.

Where as the Visnu-"sakti"-tattva and Visnu-tattva Personalities are eternal inhabitants of Vrindavana who NEVER fall down, or choose to forget Krsna because they ARE Krsna playing a different role in His own eternal pastimes and affairs.

THEY are direct expansions of Krsna Himself and are permanently part of His internal energies or potency that ARE all direct and full expansions of Krsna as varied Personalities.

For example, the Pancha-tattva are a combination of Visnu-sakti-tattva, Visnu-tattva, Siva-tattva and jiva-tattva Personalities with only one being jiva-tattva (Srivasa)

1 - Caitanya Mahaprabhu is Krsna Himself, The Supreme Person (Svayam Bhagavan).

2  - Nityananda is Krsna's first personal expansion with the combined power of Balarama

3 - Advaita Acharya is the combined power of Lord Visnu and Lord Siva (Harihara).

4 - Gadadhara Krsna's internal energy Srimati Radharani Herself who is none different from Krsna.

5 - Srivasa is Krsna's jiva-tattva pure devotee and symbolizes devotion.

Srila Prabhupada - ''Śrī Kṛṣṇa Caitanya, Śrī Nityānanda, Śrī Advaita, Śrī Gadādhara, and Śrīvās. 

Śrīvās is jīva-soul (marginal living entity). The jīva-tattva (jiva-soul), śakti-tattva, viṣṇu-tattva, these are all tattvas. So Pañca-tattva. Śrī Kṛṣṇa Caitanya is the supreme tattva, Kṛṣṇa. Śrī-kṛṣṇa-caitanya, rādhā-kṛṣṇa nahe anya. We are worshipping Rādhā-Kṛṣṇa. So Śrī Kṛṣṇa Caitanya is Rādhā-Kṛṣṇa combined." (Lecture CC Adi-lila 7.5, Mayapur, March 7, 1974)

The correct understanding is that ALL the different grades of Krsna’s living energies (living and none living) are under the broad category of sakti-tattva that means "the energies of Krsna.

Sakti-tattva (energies of Krsna) also includes ALL expansions of Krsna living and non-living-

1 - Visnu-tattva,

2 - Visnu-sakti-tattva,

3 - Siva-tattva,

4 - Jiva-tattva (marginal living entities (jiva-souls) endowed with free will).

5 - Maha-tattva (matter)

Visnu-tattva (1) and Visnu-sakti-tattva (2) are direct expansions of Krsna who are Krsna Himself playing a different roles in His own pastimes, having 60 of Krsna's 64 attributes which is 93.75% of Krsna's qualities.

Where as Siva-tattva and jiva-tattva (jiva-souls) are NOT Krsna. Siva and the jiva-souls have their his own unique personality separate from Krsna's Personality as said above.

And each individual jiva-tattva soul ALWAYS have their own unique personality, character and independence separate from Krsna's Personality and Identity,  but simultaneously dependant of Krsna's energies because Krsna IS the cause of all causes.

Srila Prabhupada - "There are Viṣṇu-tattva, Jīva-tattva and Sakti-tattva. Viṣṇu-tattva is the Supreme Absolute Truth, jīva-tattva is part and parcel, and Sakti-tattva is the energy of God." (Lecture SB, Canto 1 Ch 5 Text 15, New Vrindaban, June 19, 1969)

The Visnu-sakti-tattvas and Visnu-tattvas have 93.75% of Krsna's qualities, which meansvthey have 60 of Krsna's 64 attributes.

The jiva-tattva (jiva-souls or marginal living entities) as said above, are independent expansions of Krsna endowed with "free will" and have 78.125% of Krsna's qualities, which is having 50 of Krsna's 64 attributes.

Because of free will the jiva-souls have their own separate identity, individuality, personality and character that allows each jiva-soul to have their own unique way of expressing themselves separate from Krsna, yet simultaneously ALWAYS dependent on Krsna.

This means the jiva-souls do NOT share Krsna's personality like the Visnu-tattva and Visnu-"sakti"-tattva Forms do because the jiva-souls are NOT God (Krsna), as said above, each have their own unique independent personality separate from Krsna's and Visnu's Personalities, that allows them to express themselves in their own unique way, and voluntarily make their own contributions and offerings.

Srila Prabhupada - "We (the jiva-souls) are marginal energy (jiva-souls). Marginal means sometimes internal, sometimes external. When we are under the internal energy, that is our normal life, and when we are under the external energy, that is our abnormal life. Therefore, we are called marginal energy (jiva-souls); we can be either this way or that way. But being qualitatively one with the purusa, our tendency is to remain in the internal energy. Being in the external energy is our artificial attempt." (Letter to Lilavati, Allston, Mass, USA 25 April, 1969)

Visnu-"sakti"-tattva expansions of Krsna on the other hand, are eternally engaged in their service to the Lord because such expansions have only the desire to please Krsna or Visnu, and can NEVER be covered by Maya because they ARE Krsna playing a different role within His own pastimes.

Unlike the jiva-souls who have their own free will and separate identity with their own personality and an independent sense of self.

Therefore obviously the Visnu-tattvas and Visnu-sakti-tattva's concept of free will and independence is only to please Krsna or Visnu BECAUSE they ARE direct expansions of Krsna.

As said above, Visnu-tattvas are direct expansions of Krsna and Visnu-sakti-tattva are often expansions in cognito playing a different role in Krsna's pastimes.

This is important to understand, and explains why Visnu-tattva and Visnu-sakti-tattvas living entities can NEVER fall down from Vaikuntha or Goloka Vrindavan.

Many living entities in the spiritual worlds are Viṣṇu-tattva and Visnu-sakti-tattva expansions expansions of Krsna playing many different roles.

Vaikuntha and Goloka-Vrindavana are made up of many Visnu-sakti-tattvas servants who appear as ordinary inhabitants of Vrindavana all playing different roles, such as gopis, gopas and many, many others there.

There are also unlimited jiva-tattvas in the spiritual worlds playing many different roles in Vaikuntha and Goloka-Vrndavana as well, as servants and friend of the Krsna.

Some roles in both Vaikuntha and Goloka-Vrindavana are very difficult to know if the pastimes are played out by a Visnu-sakti-tattva, Visnu-tattva or Jiva-tattva entities.

Visnu-tattvas ARE Krsna's direct stand-out expansions such as Balarāma, Narayana, Visnu, Ramachandra, Narsinga deva etc, but there are other expansions too who maybe just simple cowherd boys (gopas) or gopis (women).

In Goloka-Vrindavana no one knows or cares who is who, if  Krsna is God or not, who is jiva-tattva (jiva-soul) or who is Visnu-tattva playing as an ordinary boy or girl?

In fact, the inhabitants of Vrindavana do not even know this little boy Krsna is the Supreme Personality of Godhead and the cause of ALL causes, nor do they care.

As already explained, Visnu-sakti-tattva and Visnu-tattva expansions can never fall down because they ARE Krsna playing another role and in His own pastimes, and may not even outwardly show they are Visnu-tattva or Visnu-sakti-tattvas in the play they are in.

And yes, in some Visnu-tattva and Visnu-sakti-tattvas roles, the Lord outwardly seems to forget they are Krsna's expansion in that role (play) or pastime they are in.

After all, Krsna can do ANYTHING He likes, He is not bound by even His own rules.

Krsna is the infinitely ORIGINAL Form of God from whom ALL His Visnu/Narayana and Visnu-tattva (jiva-souls) forms expand from, who are unlimited.

The only difference between Srimati Radharani, Lord Balarama and Krsna, is Lord Krsna IS the INFINITE Supreme Personality of Godhead and cause of all causes without a beginning and will never end.

Krsna ALWAYS has 4 MORE qualities or attributes than both Radharani (Visnu-sakti-tattva expansion) and Balarama (Visnu-tattva expansion) who only partly exhibit those qualities, yet both ARE none different than Krsna the Supreme Personality of Godhead and cause of ALL causes.

However, because they are not the original (first) form of God with ALWAYS the full 64 qualities, then not even Srimati Radharani, Krsna's eternal consort, or Balarama, Krsna's older brother are equal to Krsna in that sense because both originated from Krsna and Krsna is the first.

But only in that sense, in all other ways they ARE equal to Krsna.

Srila Prabhupada - "In the category of Visnu-tattva there is no loss of power from one expansion to the next, any more than there is a loss of illumination as one candle kindles another. Thousands may be kindled by an original candle, and all will have the same candle power. In this way it is to be understood that although all the Visnu-tattvas, from Krsna and Lord Caitanya to Rama, Narasimha, Varaha, and so on." (Adi 3.71, Purport)

One different is the original Kṛṣṇa never kills demons because He never leaves Vṛndāvana whereas Balarama already an expansion of Krsna does leave the spiritual world Vrindavana and enters the the facsimile Vrindavana in the material creation.

Srila Prabhupada - "Tattva is manifested in different ways: Viṣṇu tattva, Viṣṇu śakti tattva, jīva-tattva like that." (SB, Canto 6 Ch 2 Text 7, Sept 10, 1975)

Lord Krsna always has 64 qualities which is 100% of His own unique attributes.

1 - Visnu-tattva has 60 of Krsna's 64 qualities (the full 100%) which is 93.75%

2 - Visnu-sakti-tattva also has 60 of Krsna's 64 qualities (the full 100%) which is 93.75%

3 - Siva-tattva has 55 of Krsna's 64 qualities which is 85.938% of Krsna's full qualities.

4 - Jiva-tattva (jiva-souls) have 50 of Krsna's 64 qualities which is 78.125% of Krsna’s full qualities. The jiva-souls who have 78.125% of Krsna's qualities, can NEVER become Visnu-sakti-tattva or Visnu-tattvas 93.75% they have of Krsna's qualities, or Siva-tattva, who has 85.938% of Krsna’s 64 qualities, which is 55 qualities of Krsna's 64 attributes.

And the jiva-tattva souls can never lose their separate individual unique personality, "free will or independence" that they have eternally (given by Krsna)

All living entities are "sakti-tattva" because they are expansions of Krsna and are part of His energy (Sakti). 

This means they are simultaneously fully dependent on Krsna and independent from Krsna (meaning personality) just like the sun-rays are fully dependent on the Sun-disc.

The sun-rays emanate from the Sun-disc and depend on the Sun-disc for their existence.

The Sun-disc has no meaning without the sun-rays, and the sun-rays have no meaning without the Sun-disc.

Similarly as explained in "Nectar of Devotion" the living entities mentioned above have no meaning without Krsna, and Krsna has no meaning without the living entities.

Being part and parcel of the Lord, as explained above, the marginal living entities (jiva-tattva souls) ALWAYS have "their own"  independence, personality and sense of self separate from Krsna's Personality, making them an independent free thinking individual that expresses their own unique character serving Krsna in a "two-way" exchange of mutual respect.

Srila Prabhupada - ''The Supreme Personality of Godhead is Kṛṣṇa the maintainer of all and cause of all causes. We are "separate and none separate" from Krsna simultaneously. There are many tattvas, such as viṣṇu-tattva, jīva-tattva and śakti-tattva, but above everything is the viṣṇu-tattva, which is all-pervading. 

This all-pervading feature of the Supreme Personality of Godhead is explained in Bhagavad-gītā (10.42), wherein the Lord says-

"But what need is there, Arjuna, for all this detailed knowledge? With a single fragment of Myself I pervade and support this entire universe."

Thus Kṛṣṇa says that the entire material world is maintained by His partial representation as Paramātmā. 

The Lord enters every universe as Garbhodakaśāyī Viṣṇu and then expands Himself as Kṣīrodakaśāyī Viṣṇu (Paramatma) to enter the hearts of all living entities and even enter the atoms.

Aṇḍāntara-stha-paramāṇu-cayāntara-stham (Bs. 5.35). Every universe is full of atoms, and the Lord is not only within the universe but also within the atoms. Thus within every atom the Supreme Lord exists in His Viṣṇu feature as Paramātmā, but all the Viṣṇu-tattvas emanate from Kṛṣṇa.

As confirmed in Bhagavad-gītā (10.2)-

aham ādir hi devānām -

Kṛṣṇa is the ādi, or beginning, of the devas of this material world—Brahmā, Viṣṇu and Maheśvara. Therefore He is described here as bhagavate bṛhate." (SB Canto 8 Ch 3 text 17)

The jiva-soul has 78.125% of Krsna's qualities and are called the ''marginal energy or marginal living entities."

The jiva-souls are different living entities from the more direct expansions of Krsna who are the Visnu-"sakti"-tattvas and Visnu tattvas however, all can play the part of gopi and cowherd boy in Krsna lila. Vaikuntha and Goloka Vrindavana have so many expansions of Krsna that it is mind boggling.

As said above, the individual more independent jiva-souls can also play the role of a gopa (cowherd boy) or gopi (cowherd girl) just like a Visnu-sakti-tattva and Visnu-tattva direct expansions of Krsna do however, the jiva-souls can NEVER become Visnu-"sakti"-tattva or Visnu-tattva. This is because the Visnu-sakti-tattva and Visnu-tattva ARE Krsna Himself who can expand as multiple personalities playing different roles in His own pastimes.

The jiva-souls ALWAYS have the ability to make their own choices of how to serve the Lord in Vaikuntha or Goloka-Vrindavan as themselves (their spiritual identity svarupa) or not serve the Lord if they choose.

And can also play other roles including Brahma in the material creation too.

The marginal living entities (jiva-souls) ALWAYS remain jiva-soul with ONLY 78.125% of Krsna’s 100% qualities, and can NEVER become God, whom are Visnu-tattva or Visnu- sakti-tattva, or even Siva who is in a leag?ue of his own being neither Visnu-tattva or Jiva-tattva.

The jiva-tattvas, unlike Visnu-sakti-tattva and Visnu-tattvas, can 'choose' to forget Krsna if they desire and therefore enter the material creation of Maha-Visnu and foolishly think they are an independent god.

The Visnu-tattvas and Visnu-sakti-tattva ARE direct expansion of Krsna who only act out the will of Krsna because they ARE an expansion of Krsna's Identity. 

Krsna actually plays out different roles, like Maha-Visnu and Garbhodakashayi Visnu who create and manage the material creation on behalf of Krsna.

Our eternal constitution position and eternal spiritual body is in Vaikuntha or Goloka-Vrindavana situated in the "eternal presence" of the spiritual world.

We just have to wake up from this temporary material dream and return back home back to Godhead, our real home.

Just like Jaya and Vijaya's eternal position as gatekeepers of Vaikuntha is always there waiting for their return from falling down into the material creation.*×..×*.