Into what four castes was Hindu society clearly divided?

They were (by rank)

priests and educated people

warriors

merchants

workers

Brahmin - priests/teachers, Kshatriyas - warriors/rulers, Vaishya - merchants/landowners, Sudra - commoners/peasants/servants, and finally there are the untouchables, who the people of India believe are not included in their caste system because they are so low in rank. They are generally people who clean the latrines and sweep the streets