In the 24th chapter the Lord instructs His dear devotee Uddhava, in the doctrine of Sankhya, realizing which a man bids fair to shed at once the delusion occasioned by false knowledge. In Krita Yuga, there was complete concordance between the understood meaning of and the words of the Vedas; people living in that age being prescient and wise understand the Vedas as they are.
People in Treta Yuga understand the Vedas in a confused way (either this or that) and in Dwapara Yuga in a contrarian fashion according to their varying comprehensions. People in each age understand the meaning as per their deserts, as determined by and under the control of the Lord. The process of creation of Brahmanda (the cosmic egg) is described with its vaikarika ahankara (through which are evolved the eleven deities presiding over ten indriyas and mind), taijasa ahankara (through which are evolved the ten indriyas) and tamasa ahankara,(the source of the five tanmantras or subtle elements and thence the gross elements).
The Lord entered the Brahmanda as it lay on the waters-Garbodha-the support of the egg,as its Controller. From His navel sprang up the Lotus on which the Fourfaced Chaturamukha Brahma appeared, from which were created the fourteen lokas, seven subterranean and seven higher and their inhabitants such as gods, asuras, nagas, siddhas, humans, and so on. The goals to be reached by yoga, askesis, and jnana (knowledge) are attainment to the successively higher spheres of maharloka, janoloka, tapoloka and satyaloka.
Through bhakti yoga, one attains to the Lord’s Abode, Vaikunta. These worlds flowing in the stream of the three gunas and yoked to karma that is impelled by the Lords potencies such as knowledge etc, are created and destroyed time and again. Minute or large, lean or stout, whatever entity has come into being is made up of both prakriti (matter) and purusha (spirit). Brahman, the efficient cause of creation, impels the evolution into mahat etc, from the material cause prakriti.
The entire universe is under the Sovereign control of Sri Hari. He is the sole and only all independent Sovereign. As long as the process of creation continues, the process of maintenance (sustenance) also follows.Creation, maintenance , again creation,again maintenance. This cycle lasts till dissolution. When Sri Hari wills so, dissolution occurs. The (reverse) process of dissolution is described whereby the entire creation is ultimately withdrawn back into the Lord.