Regarding IV in nse option chain

Hai & Hello everyone,
Please anyone explain IV in nse option chain .Please explain with examples. Why IV is different for Call option and Put option and what is reason . Some time both are equal and some time slightly different and some huge different such as 15 15, 20 20 ,20 25,20 30,30 40.who makes the changes? Why it changes every day? What is the IV for option buying and what is IV for NO option buying?what is the IV for option seller? What is the IV for premium erosion? Is it really IV makes impact in NIFTY AND BANKNIFTY (Not for stocks only index). By using IV in BANKNIFTY can we make profits? .Is it IV important for option buying?Please clarify my doubts…