Theoretically, Jati system is a combination of two kinds of principles. One kind is based on differences and distance. The other kind is based on universality and power hierarchy (chain).
Each Jati is supposed to be different from others. Therefore each Jati was expected to keep away from other Jatis. Most of the rules and regulations of Jati are formulated on the principle of preventing the mingling of Jatis. Thus there were restrictions regarding marriage and ‘panthibhojanam’ (eating together).
At the same time a Jati can’t survive by itself. It can survive only as part of larger community. And this is its universality. The community (society) as a whole is not based on any principle of equality. There is a hierarchical order there. It is like a ladder. In this ladder each Jati is given its place.
Jati is a combination of two kinds of concepts:
a) Differences and distance from other Jatis.
b) Part of a larger community and part of a power hierarchy.