A smart contract is a self-executing program deployed on a blockchain that automatically executes actions when predefined conditions are met. Smart contracts run on-chain — they cannot be modified or stopped by any single party once deployed, and their execution is transparent and verifiable.

On Solana, smart contracts are called programs. They are written in Rust and compiled to run on Solana's runtime. Programs like token lockers and staking pools are examples of smart contracts that enforce specific rules — such as preventing token withdrawals before an unlock date.

Smart contracts eliminate the need for intermediaries in financial transactions. Because execution is automatic and on-chain, participants do not need to trust any third party — they only need to trust the code.