Hindus believe time is cyclical. Hindus also believe that society is divided up into different groups called varnas and that within these there are further sub-groups called castes or jatis . Where a person is reborn is determined by their karma . Hindus try to do good things so that they will increase their good karma and so be reborn higher up the caste system. The process of being being born, growing, dying and being reborn again is called samsara.
People basically get what they deserve as a result of their own actions.
Hindus, on the other hand, believe humans are not sinful as such but are simply ignorant of their true nature. Freedom from samsara comes once a person realise they are actually divine and belong to God. The idea of reincarnation is not strictly limited to Hinduism. The idea of reincarnation is also becoming more popular in Britain as people use hypnotic techniques to undergo past life regression in order to explore why they are the people they are today. Despite what you might think, there are some who genuinely and sincerely believe they are the reincarnation of certain people from previous lives.