Smart Contract
A smart contract is a means of programmatically exchanging value (currency and assets) on the Internet using blockchain.
Prior to smart contracts, the ways to exchange value were either:
Meeting in person and exchanging actual cash (e.g., trading dollars in your pocket for the item you want to purchase)
Using a trusted, centralized authority. For example, a bank, brokerage or escrow company would be trusted to finalize a transaction for you.
In contrast, smart contracts allow you to write code that exchanges value without any parties needing to trust each other, meet each other and without the intervention of third-party authorities. This can be compared to how the Internet and World Wide Web enabled new classes of information via decentralized information exchange, enabling disruptive applications that required no permission to publish—as well as the “small pieces loosely joined” ability to create cooperative networks of code.
Smart contracts have the potential to be as disruptive to finance, art, collecting, real estate, gaming and other industries in the same way that decentralized Web publishing disrupted many other information-intensive industries. Some of the key applications of smart contracts include decentralized finance (DeFi) and non-fungible tokens (NFTs).
Further Exploration
Smart Contracts: the Ultimate Guide for Beginners (Hasib Anwar)