Solidity
The dominant programming language for writing smart contracts that run on Ethereum and other compatible virtual machines.
Solidity is a statically typed language with syntax borrowed from JavaScript and C++. Code compiles to bytecode that the Ethereum Virtual Machine executes. Because most chains adopted the EVM, learning Solidity unlocks Ethereum, Polygon, BNB Chain, and dozens of others. It has been the default for DeFi and NFT contracts since 2015.
The language is unforgiving. A deployed contract is immutable, so a single bug can drain it permanently, and reentrancy or access-control mistakes have caused enormous losses. Serious projects pay for audits before launch. Alternatives like Vyper exist but never displaced it.
Related terms
Self-executing code on a blockchain that runs exactly as written when its conditions are met, with no party able to intervene.
EVM (Ethereum Virtual Machine)The runtime that executes smart contracts on Ethereum and many other chains, defining how their code runs.
Smart Contract AuditA structured review of contract code that hunts for vulnerabilities before attackers find and exploit them.
Reentrancy AttackAn exploit where a contract is called back mid-execution, draining funds before its balances update.