EVMs

The Ethereum Virtual Machine (EVM) is the runtime environment used by the Ethereum blockchain to execute smart contracts. It acts as a global, deterministic state machine that runs on every full node, ensuring that contract code behaves the same way across the network. The EVM executes bytecode for accounts that contain contract code and for externally owned accounts that initiate transactions.

The EVM is a stack-based, 256-bit word architecture with its own memory and persistent storage. It processes operations through a defined set of opcodes, manipulating data, making calls to other contracts, and interacting with blockchain state. Code execution is isolated and deterministic: a contract cannot perform arbitrary I/O or access the outside world directly, and all interactions are mediated by the Ethereum protocol. Contracts are stored on-chain, and their code is executed whenever they are called by transactions or by other contracts.

Smart contracts are typically written in high-level languages such as Solidity or Vyper and compiled into EVM bytecode before deployment. Once deployed, the bytecode resides at a contract’s address and runs in response to transactions and internal messages. Gas is the computational resource metered for each operation, with a gas limit that constrains how much work can be done in a transaction or block. The sender pays for gas in Ether, which helps prevent abuse and ensures network resources are allocated efficiently.

Multiple Ethereum clients, such as Geth, Besu, and others, implement the EVM, enabling widespread participation. The same EVM bytecode can run on compatible networks, allowing cross-chain deployment of contracts and interoperability across EVM-compatible chains.