They all derived from Sindhu, which was the river referred to in the Vedas, and then changed into Hindu, Indus, and things like India. Now, also in the Vedas is the first time that we have reference to a stratified social structure. And we see that with the varnas that are referred to, where at the top you have the, and you could view these as social roles or classes. At the top you have the Brahmins, the priests, the scholars, and the teachers. Then the next you have the kings and the warriors, referred to as the Kshatriyas. Then the Vaishyas, who are the farmers, the merchants, the artisans. And then the Shudras, the laborers.