A paramilitary force is a semi-militarized force whose organizational structure, tactics, training, subculture, and (often) function are similar to those of a professional military, but which is not included as part of a state's formal armed forces. Though paramilitary is not a military force, it is usually like military's light infantry force in terms of training, and organizational structure.
Paramilitary force like B&F, which is for border guarding, comes under the Army during war and performs some functions of infantry.
Indian Paramilitary Forces refer to three organisations that assist the Indian Armed Forces closely and are led by officers of the Indian Army or Indian Navy. However, any law or rules of the Government have not defined them. Earlier, the term 'paramilitary' forces was used for eight forces:
Special Frontier Force
Indian Coast Guard
Central Reserve Police Force
Border Security Force
Indo-Tibetan Border Police
Central Industrial Security Force
Sashastra Seema Bal
However, from 2011, they have been regrouped into two classes whereby the later six are called Central Armed Police Forces (CAPF). The first three are the current paramilitary forces of India - Assam Rifles (part of Home Ministry), Special Frontier Force (part of Cabinet Secretariat) and Indian Coast Guard (part of Ministry of Defence).