Since it is said that Lord Kṛṣṇa never leaves Vṛndāvana-dhāma, one may ask how He manages the affairs of the creation. This is answered in the Bhagavad-gītā (13.14-18): The Lord pervades the entire material creation by His plenary part known as the Paramātmā, or Supersoul. Although the Lord personally has nothing to do with material creation, maintenance and destruction, He causes all these things to be done by His plenary expansion, the Paramātmā. Every living entity is known as ātmā, soul, and the principal ātmā who controls them all is Paramātmā, the Supersoul.
This system of God realization is a great science. The materialistic sāṅkhya-yogīs can only analyze and meditate on the twenty-four factors of the material creation, for they have very little information of the puruṣa, the Lord. And the impersonal transcendentalists are simply bewildered by the glaring effulgence of the brahmajyoti. If one wants to see the Absolute Truth in full, one has to penetrate beyond the twenty-four material elements and the glaring effulgence as well. Śrī Īśopaniṣad points toward this direction, praying for the removal of the hiraṇmaya-pātra, the dazzling covering of the Lord. Unless this covering is removed so one can perceive the real face of the Personality of Godhead, factual realization of the Absolute Truth can never be achieved.
The Paramātmā feature of the Personality of Godhead is one of three plenary expansions, or viṣṇu-tattvas, collectively known as the puruṣa-avatāras. One of these viṣṇu-tattvas who is within the universe is known as Kṣīrodakaśāyī Viṣṇu. He is the Viṣṇu among the three principal deities-Brahmā, Viṣṇu and Śiva-and He is the all-pervading Paramātmā in each and every individual living entity. The second viṣṇu-tattva within the universe is Garbhodakaśāyī Viṣṇu, the collective Supersoul of all living entities. Beyond these two is Kāraṇodakaśāyī Viṣṇu, who lies in the Causal Ocean. He is the creator of all universes. The yoga system teaches the serious student to meet the viṣṇu-tattvas after going beyond the twenty-four material elements of the cosmic creation. The culture of empiric philosophy helps one realize the impersonal brahmajyoti, which is the glaring effulgence of the transcendental body of Lord Śrī Kṛṣṇa.