Citizenship 

It is a legal concept which can be acquired by two ways :-

(a) When a person is born in India , he acquires automatic citizenship of India. 

(b) A person born outside India applies for citizenship and Indian law allows him . 


Residentship 

It is an economic concept - an individual is a normal resident of a country if he ordinarily resides in the country for a period more than one yea and his centre of economic interest also lies in that country.