The Lord has unlimited energies, but all of these energies can be divided into three main categories.
Is everything a part of Krishna and connected to Him?
Why is the material world called the external energy or Krsna's separated energy (bhinna-prakriti)?
Sunshine and clouds come from the sun; thus they are simultaneously one with the sun and different from the sun. Similarly, the living entities and the material creation come from Krishna and are thus simultaneously one with and different from Krishna.
Stha means position.
Tata is the point at the edge of the waves that roll up on the beach, the margin between water and land.
The living entities, the marginal energy of the Lord, are compared to sea-weed that can drift in the ocean waves or wash up on the shore.
This divine energy of Mine, consisting of the three modes of material nature, is difficult to overcome. But those who have surrendered unto Me can easily cross beyond it. (Bhagavad-gita 7.14)
O son of Prtha, those who are not deluded, the great souls, are under the protection of the divine nature. They are fully engaged in devotional service because they know Me as the Supreme Personality of Godhead, original and inexhaustible. (Bhagavad-gita 9.13)
If you don't take shelter of the internal energy, you will remain in the shelter of the external energy. The living entity is always under the shelter of one of these two. You cannot be outside of both. You cannot realise one while in the other.
Antaranga-sakti includes everything in the spiritual world and is under the direct shelter of the spiritual energy.