Ethereum and the EVM
Ethereum is a replicated state machine, and the EVM is the deterministic computer that updates its state.
The EVM explains smart contracts, gas, execution, storage, reverts, and why all validating nodes can independently verify state transitions.
The Intuition
Ethereum nodes all run the same transactions in the same order and reach the same state. Smart contracts are programs stored on-chain and executed by the EVM.
See it concretely
Imagine thousands of judges applying the same rulebook to the same ordered cases. If the rulebook is deterministic, they all produce the same final ledger.
Tempting — but wrong
The precise version
Ethereum state maps addresses to accounts. Externally owned accounts are controlled by private keys, while contract accounts contain code and storage. A transaction may transfer value, call contract code, create contracts, emit logs, and modify state. Successful execution persists state changes; reverted execution rolls back state changes but still consumes gas.
state_{n+1} = \Upsilon(state_n, block_n)Check your understanding
Why must EVM execution be deterministic?
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What is the difference between an EOA and a contract account?
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- Explain Ethereum as a state machine.
- Distinguish EOAs and contract accounts.
- Explain storage, memory, calldata, and logs.
- Explain success, revert, and gas consumption.
Why must EVM execution be deterministic?