The runtime that executes smart contracts on Ethereum and on the many chains that copied it, which is why one contract can deploy to Polygon, Arbitrum, BNB Chain, and Base.
EVM compatibility decides how much of the ecosystem you inherit for free — wallets, tooling, auditors, libraries — and how cheaply you can expand to another network later.
We write EVM contracts to deploy across chains from one codebase, and we test per chain anyway, because gas costs, block times, and precompiles differ more than the marketing suggests.