Smart contracts are self-executing contracts with the terms of the agreement directly written into lines of code. They run on a blockchain and automatically enforce and execute the terms of a contract when predefined conditions are met. Smart contracts eliminate the need for intermediaries, reducing costs and increasing efficiency.
They can be used for a variety of applications, such as financial agreements, automated governance, and decentralized applications. The Ethereum platform, known for its robust smart contract capabilities, has popularized their use, but many other blockchain platforms also support smart contracts.