The entire Universe is reverberating. When there is reverberation, there is sound. In other words, the entire cosmos is simply a manifestation of sound energy. The ancient Vedic sages through penance, could download cosmic data directly. They received cosmic truths in the form of sounds which they envisioned. These truths were recited as received, and passed on generations after generations.
Various truths downloaded by various ṛṣi-s gave rise to the ocean of Vedas. Veda Vyāsa later compiled these Vedas and classified them. This is how the 4 Vedas came to existence. Each of these Vedas had many branches. Each branch had 4 components :
(1) saṃhitā
(2) brāhmaṇa
(3) āraṇyaka
(4) upaniṣad
Camakam is from the Taittirīya Saṁhitā, Kṛṣṇa Yajurveda, 4th Kāṇḍa, 7th Prāpaṭhaka

