This material world is going on in that way: birth, then existence, then development, then by-product, then dwindling, then vanishing. Six changes, everything. Either take your this body or a fruit or a flower, anything material you take, these six changes are there. First of all birth, then growth, then existence, then by-product, then dwindling, then vanishing. Six changes. Everything. Either take your this body or a fruit or a flower, anything material you take, these six changes are there: first of all birth, then growth, then existence, then by-product, then dwindling and then vanishing.
So Vedānta-sūtra says, janmādy asya yataḥ. The original source of birth, the source of maintenance, the source of growth, the source of development and the source of dwindling, and after all, vanishing, or the conservation of the vanishing elements, everything is the Supreme Brahman.
So this janmādy asya śloka has been interpreted in various ways, but the most important commentator is Vyāsadeva. He's the original writer of Vedānta-sūtras. Not only he's the writer of Vedānta-sūtra, he's the writer of all Vedic literature. Vedic literature means four Vedas: Sāma, Atharva, Yajur and Ṛk. And from the Vedas, there are Upaniṣads.
There are 108 Upaniṣads. And there are Purāṇas. Purāṇas means those who will not understand the Vedic aphorism and the Upaniṣads, statement of the Upaniṣads, for them, for ordinary men, there are many stories. The stories are concluded with the Vedānta-sūtra.
Then there is Mahābhārata. You have heard all these names. Mahābhārata, the history, history of Indian royalty. The Mahābhārata is the history of fighting between two groups of royal family, the Pāṇḍavas and the Kurus. And in that Mahābhārata you'll find all kinds of sociology, politics, religion and military science.