Options chain can be defined as the listing of all option contracts. It comes with two different sections: call and put. A call option means a contract that gives you the right but does not give you the obligation to buy an underlying asset at a particular price and within the option's expiration date.
While not foolproof, option chains offer insights into market sentiment through implied volatility and open interest. High implied volatility suggests expected price swings, while option volumes can indicate potential support or resistance levels.