The caste system is an ancient way of deciding which social group people belong to. In India, there have traditionally been four main caste groups - Brahmin (priests and teachers), Kshatriya (warriors and rulers), Vaishya (traders and merchants), and Shudra (labourers and servants). People cannot move from one caste group to another - so if your parents are in one group, you will be in the same group too. This system also means that some people will have more advantages and opportunities than others, depending on their family's caste group.