The Ethereum Virtual Machine is a decentralized computation engine that executes smart contract transactions through the Ethereum network. Integral to the Ethereum ecosystem, EVM allows developers to create and operate decentralized applications (dApps) independent of third parties.
https://www.coinbase.com/learn/crypto-glossary/what-is-the-ethereum-virtual-machine
https://www.quicknode.com/guides/ethereum-development/getting-started/what-is-the-ethereum-virtual-machine-evm
https://www.techopedia.com/definition/ethereum-virtual-machine-evm