Communities in India are considered as historically marginalized and disadvantaged communities. They have faced social, economic and political exclusion and discrimination for centuries. The Indian Constitution recognizes this and provides for affirmative action in the form of reservations in education, employment and political representation.

Scheduled Castes (SCs) are also known as Dalits and they constitute about 16.6% of the Indian population. They were historically considered as the lowest of the low in the caste hierarchy and were subjected to various forms of discrimination and oppression.

Scheduled Tribes (STs) constitute about 8.6% of the Indian population and they are the indigenous people of India. They have a distinct culture, language and way of life. They have also faced discrimination and marginalization due to their socio-economic status and lack of access to resources.

Other Backward Classes (OBCs) constitute about 40% of the Indian population and they are the socially and educationally backward classes who have been historically marginalized. They are not considered as untouchables like the SCs but they have faced discrimination and exclusion due to their caste status.

The reservation policy in India provides for a certain percentage of seats and jobs to be reserved for these communities in order to ensure their representation and participation in various fields. However, there are also debates and criticisms regarding the efficacy and fairness of the reservation policy.