A smart contract is a computer program or code that is stored and executed on a blockchain. It enforces and executes the terms and conditions written within its code. Smart contracts do not rely on third parties to enforce the programming logic defined in the code. Instead, the execution and enforcement of the program are carried out by the decentralized network of computers running the blockchain. Smart contracts can facilitate a wide range of functions, such as transferring digital assets or triggering specific actions based on predefined conditions.