ORAL COMPREHENSION - THE CASTE SYSTEM
The caste system in India corresponds to a system of social stratification existing for centuries and mainly rooted in the Hindu tradition. People are divided into five groups / castes. It was originally based on a division of labor (people belonged to a caste according to their occupation).
When someone is born into a class, it is impossible to change it. It is also impossible to intermarry. The main problem is that this system prevents people of the lower castes from climbing the social ladder.

Here are some videos to learn more about the Caste System in India.
Explainer: Is India's Caste System Still Alive? : DNews
India is growing fast, yet the outlawed caste system still creates discrimination. So what is the Indian caste system? And how is it affecting modern India?
http://news.discovery.com/human/videos/is-indias-caste-system-still-alive-150422.htm
