The Caste system is a system in India that was once mainly used by Hindus. It started as a job system but later became a social class system that depends on ones ancestry. This system has been generally accepted for about 3000 years. There are four castes in this system, and one class regarded as the "Untouchables". There are also castes in some countries other than India as the system spread to South Asia about 2000 years ago.