A binary option is a financial product that pays either a fixed amount of an asset or nothing at all. It is a bet on an asset. At maturity, if the asset is above the strike, the option will payout an amount at maturity.
For a call option, the payoff at maturity is one dollar, provided that the basket price is greater than the strike; otherwise, it is zero. For a put option, the payoff at maturity is one dollar, provided that the asset price is below the strike; otherwise, it is zero.