A Caste is the place which a person is born. In Hinduism, the lowest caste are the workers and the highest caste are the Brahmin Priests, the cows are also considered like Brahmins . Not all Hindus accept the caste system, some see caste as an aberration of original Hindu teachings,  the caste system is legally banned. The Dalits are treated even worse than the workers. Dalits are either very low cast or so low they don't even have a caste. And accrding to Hinduism all foreigners who are not Indians or descended from Indians are without caste. Most people reading this are Dalits.
For a person to go up, they have to be good in their caste. This means no complaining, and to do whatever their caste requires. If they're a beggar, they must beg. If they're a king, they must rule. If they're a fish, they must swim. The caste system is almost abolished in towns but it carries on in rural areas.