Is someone at the top? Is someone at the bottom? Is it consistent what the person at the top looks like or can it sometimes by a black person or a muslim or someone who is gay?

They have a caste system in India. In descending order, the classes are as follows:

Brahmana (now more commonly spelled Brahmin): Consist of those engaged in scriptural education and teaching, essential for the continuation of knowledge.
Kshatriya: Take on all forms of public service, including administration, maintenance of law and order, and defense.
Vaishya: Engage in commercial activity as businessmen.
Shudra: Work as semi-skilled and unskilled laborers.

Why do Americans have the phrase "at the bottom of the barrel"?