This tag is to be used for any question on Options, A more specific tag [put-options, call-options, options-assignment, option-exercise] should be used when appropriate.
An option is a contract to buy or sell a specific financial product. This product is known as the option's underlying instrument or underlying interest. For equity options, the underlying instrument is a stock, exchange traded fund (ETF) or similar product. Put options are contracts to sell and Call options are contracts to buy.