Definition
The Ethereum Virtual Machine (EVM) defines how executable contract instructions affect Ethereum’s state. It provides a shared computational model so that nodes processing the same valid input under the same protocol rules can obtain matching results. It is a logical execution environment, not a single physical computer.
How It Works
Contracts written in supported languages are compiled into bytecode that the EVM interprets. Operations consume gas, limiting computation and charging for resource use. A transaction can invoke contract functions, change storage or trigger calls to other contracts. If execution fails, many intended state changes are reverted, although fees can still be charged.
Key Considerations
EVM compatibility helps developers reuse tools across networks, but does not make those networks identical. Protocol versions, supported instructions, fees and security assumptions may differ. The EVM also cannot independently establish the truth of external events; applications commonly use oracles for such inputs. A contract running successfully in the EVM can still contain flawed business logic, unsafe permissions or exploitable interactions.