There are four main castes usually listed in the following order; Brahmins, the teachers/priests, Kshatriyas, the warriors and administrators, Vaishyas, the traders and the Shudras, the labourers. This system originally developed as method of division of labour and thus the analogy of the different parts of the body. In very little time though, even as early as the Later Vedic Era, the system became thoroughly corrupted. People began to lose the freedom to move between the castes based on one’s choice of profession. Caste became a matter of birth.
If you go deep enough into one thing, you will reach the infinity of existence within it. This is true of all fields. A musician touches the infinite connection when touched with inspiration. Tunes are given, just as words to an inspired poet. Given from where?