The architecture shown in this article has inaccuracies. Do not use it as a reference until updated (if ever). In the meantime, refer to the official Starknet docs.
tl;dr
- Starknet’s user accounts (wallets) are implemented as smart contracts.
- The system has 3 off-chain components (Sequencer, Prover and Full Nodes) and 2 on-chain (Verifier and Core).
- The current system architecture is able to handle more transactions than Ethereum but with a higher delay for finality.
- A dual checkpoint mechanism has been proposed to reduce time to finality without compromising cost.
- An L2 transaction can be on any of these states: NOT_RECEIVED, RECEIVED, PENDING, ACCEPTED_ON_L2, ACCEPTED_ON_L1 or REJECTED.