Ethereum Overview
Part 1: Ethereum as a Shared Execution System
Section titled “Part 1: Ethereum as a Shared Execution System”Ethereum is a decentralized execution system where execution clients deterministically compute state transitions, and consensus clients apply fork-choice and finality rules to select canonical history.
- State = current Ethereum data (account balances, nonces, contract storage)
- State transition = deterministic post-state after full execution payload processing (transactions plus protocol-defined block processing)
- Deterministic execution = same pre-state + same payload produces the same post-state on every honest execution client
Part 2: Foundational Pillars
Section titled “Part 2: Foundational Pillars”1. Ethereum protocol components
Section titled “1. Ethereum protocol components”- Execution layer (EL): transaction gossip, mempool, execution payload construction, EVM execution
- Consensus layer (CL): proposer/attester duties, fork-choice, justification/finalization
- Transactions: signed state-transition messages
- Consensus objects: beacon blocks, slots, and checkpoints
- Execution objects: execution payloads embedded in beacon blocks
- Incentives: issuance, base-fee burn, priority fees, and penalties/slashing rules
2. Proof-of-Stake (PoS)
Section titled “2. Proof-of-Stake (PoS)”- Validators stake ETH and participate in proposal and attestation duties.
- Fork-choice selects the head block from weighted attestations.
- Finality is checkpoint-based (justified/finalized) under supermajority voting assumptions.
- PoS replaced PoW mining on Ethereum mainnet in 2022.
3. Ethereum Virtual Machine (EVM) - State Machine
Section titled “3. Ethereum Virtual Machine (EVM) - State Machine”- The EVM is Ethereum’s execution runtime.
- Execution clients re-execute transactions in execution payloads to validate proposed state transitions.
- Valid payload execution updates account state roots deterministically.
4. Smart Contracts
Section titled “4. Smart Contracts”- Smart contracts are on-chain programs.
- They execute according to code and network rules.
- They enable DeFi, tokens, DAOs, identity workflows, and many other dApps.
- Security is critical because contract bugs can be financially exploitable.
5. Clients
Section titled “5. Clients”Ethereum runs as two coordinated client stacks:
- Execution clients (for example Geth, Nethermind, Erigon, Besu) execute EVM transactions and maintain EL state.
- Consensus clients (for example Lighthouse, Prysm, Teku, Nimbus, Lodestar) run PoS fork-choice and finality logic.
Operators combine one EL client and one CL client to run a full post-Merge node. Ethereum for Go developers
6. Turing Completeness
Section titled “6. Turing Completeness”Ethereum’s EVM is considered Turing-complete in the theoretical sense because it supports conditional branching and unbounded computation in principle.
- Conditional branching: JUMPI enables branch-dependent control flow.
- Looping: JUMP/JUMPI plus comparisons can implement loops.
- Storage (persistent state): SSTORE/SLOAD modify/read contract storage committed to global state.
- Memory (ephemeral per call): MSTORE/MLOAD modify/read transient memory for the current execution context.
Gas bounds execution in practice: without gas, the network could not safely cap runtime for potentially non-terminating programs.
Part 3: Quick Comparison (Bitcoin vs Ethereum)
Section titled “Part 3: Quick Comparison (Bitcoin vs Ethereum)”| Dimension | Bitcoin | Ethereum |
|---|---|---|
| Primary goal | Digital money settlement | Programmable blockchain platform |
| Execution model | Limited scripting | General-purpose smart contracts (EVM) |
| Native asset | BTC | ETH |
| Mainnet consensus today | PoW | PoS |
Step-by-Step Reading Map
Section titled “Step-by-Step Reading Map”| Step | What Happens | Read This File |
|---|---|---|
| 1 | Node roles, client architecture, and deployment basics | eth-node |
| 2 | Peer discovery, gossip, and propagation in the network | eth-p2p |
| 3 | Cryptographic primitives, signatures, and verification model | eth-elliptic-curve |
| 4 | Merkle trees, MPT roots, and Verkle roadmap concepts | eth-merkle-trie |
| 5 | User identity and account model (EOA/contract) | eth-account |
| 6 | Wallet models, custody, and account abstraction mental model | eth-wallet |
| 7 | Hands-on EOA keystore and local-signing workflow (Python) | eth-wallet-diy |
| 8 | Transaction fields (nonce, to, value, data, signature) | eth-transaction |
| 9 | Fee setup (gasLimit, maxFeePerGas, maxPriorityFeePerGas) | eth-gas |
| 10 | CL proposer/attester roles, fork-choice, and finality checkpoints | eth-pos |
| 11 | EL runtime execution path and block import re-validation | eth-transaction-code |