Futures Trading

What is an "Underlying" and how is it different than "Contract"?

An index or stock enabled for trading on futures is called an "Underlying" e.g. NIFTY (index) and ACC (stock). There may be various tradable contract for the same underlying based on its different expiration period. For example Fut - ACC - 31 Aug 2023, Fut - ACC - 28 Sep 2023 and Fut - ACC - 26 Oct 2023 are "contracts" available for trading in futures having ACC as "underlying".