A derivative is a financial instrument whose value is dependent on an underlying asset. The main types of derivatives are forwards, futures, options, and swaps. Forwards are customized contracts to buy or sell an asset at a future date at a fixed price. Futures are exchange-traded contracts with standardized terms. Options provide the right but not obligation to buy or sell an asset at a future date at a specified price. Swaps involve exchanging cash flows of two parties over time based on some underlying factors. Derivatives allow for hedging risks and speculating on market movements.