An options contract gives the buyer the right, but not the obligation, to buy or sell an underlying asset at a specified strike price on or before the expiration date. There are call and put options. A call option allows buying the asset, while a put option allows selling the asset. The buyer pays a premium to the seller for this right. The profit/loss of the buyer and seller depends on whether the option expires in or out of the money. The buyer's potential profit is unlimited but their loss is limited to the premium paid, whereas for the seller the potential loss is unlimited but profit is limited to the premium received.