What is the main difference between the position of the head of state in India and that of the USA?

 India is a Republic because the head of the state is the President who is elected by the Electoral
College of the Parliament and the State Legislative Assembly for a fixed period of five years.
The difference between the position of the President of India and the USA is that in the USA, the
President is the head of the presidential form of democratic government (real head of executive)
whereas in India, President is the head of the parliamentary government, i.e. Prime Minister and
his Cabinet is real executive and the President is the nominal head of the state.