A smart contract is a computer program or a transaction protocol that is intended to automatically execute, control, or document legally relevant events and actions according to the terms of a contract or an agreement.
A smart contract is an agreement that is written in code rather than a physical paper agreement or verbal contract. It creates an agreement between several parties that agree on specific events in the past, present, and future. Most common smart contracts are written on the Ethereum network using something called "solidity." They are immutable. This means they cannot be changed once they come into use.
They are "distributed among the network connected to different nodes (computers)", which verifies the conditions if they are met.
Smart contracts are self-executing lines of code with the terms of an agreement between buyer and seller automatically verified and executed via a computer network.
Benefits of Smart contracts
Once an event is satisfied, the contract is executed immediately without any paperwork as it is a digital contract.
As it is present in the blockchain, it makes them very hard to hack.
Smart contracts remove the need for intermediaries to handle transactions.