Accounts and State

Ethereum's world state is the complete snapshot of all accounts and their data at a given moment.

Every transaction transforms this state from one valid version to the next. Accounts are the building blocks of that state.

Ethereum has exactly two account types:

• Externally Owned Accounts (EOAs) — controlled by private keys (users)
• Contract Accounts — controlled by their code

Both share the same 20-byte address format.