Ethereum
Bitcoin is digital gold; Ethereum is a programmable computer the whole world shares. Open it up.
How Ethereum actually works — the world computer and the EVM, accounts vs Bitcoin's UTXO, gas and fees under EIP-1559, smart contracts and tokens (ERC-20 and ERC-721), proof-of-stake and staking, and Layer-2 rollups — all from zero.
Bitcoin made a shared ledger that records payments. Ethereum asks the bigger question: what if that same ledger could run programs, not just track money? That one twist turns a payment network into a world computer — a single machine thousands of nodes run in lockstep, where anyone can deploy code that executes exactly as written and no company can alter or switch off.
This topic opens it all the way up, assuming nothing beyond crypto-basics. You’ll build it as a ladder, one rung per concept:
- Ethereum vs Bitcoin — why a programmable chain needs a different design.
- The EVM, the world computer — how a transaction becomes a deterministic change to shared state.
- Account model vs UTXO — Ethereum’s bookkeeping contrasted with Bitcoin’s.
- Gas and fees under EIP-1559 — the meter that makes it pay for itself, where part of every fee is burned.
- Smart contracts and tokens — where a “token” turns out to be just a balance sheet inside a contract (ERC-20 for fungible coins, ERC-721 for NFTs).
- Proof-of-stake and staking — how Ethereum secures itself without mining.
- Layer-2 rollups — how it scales to cheap transactions without giving up base-chain security.
Get these seven and Ethereum stops being a buzzword and starts being a machine you understand.
In this topic
- 1 What Ethereum Is and How It Differs from Bitcoin Ethereum from zero: a programmable, decentralized world computer. What ETH is, why a smart-contract chain needs a different design than Bitcoin, and what 'programmable money' really buys you. 9 min
- 2 The EVM: Ethereum's World Computer How Ethereum's shared computer works: the EVM as a deterministic state machine, world state, transactions as state transitions, why every node re-executes everything, and what bytecode and 'Turing-complete' really mean. 9 min
- 3 Accounts vs Bitcoin's UTXO Model Two ways to track who owns what: Bitcoin's UTXO 'cash and coins' model vs Ethereum's account 'bank balance' model. Externally-owned vs contract accounts, the nonce, and why programmable money prefers accounts. 8 min
- 4 Gas and Fees: Paying the World Computer How Ethereum fees work: gas as a unit of computational work, the gas limit, and EIP-1559's base fee (burned) plus priority tip (to the validator). Why fees spike when the network is busy, and how to read a fee in gwei. 9 min
- 5 Smart Contracts and Tokens (ERC-20 and ERC-721) What a smart contract actually is — code that lives at an address and runs deterministically — and how tokens are built on top: ERC-20 fungible tokens as a balance mapping, ERC-721 NFTs as unique IDs, and why standards matter. 10 min
- 6 Proof-of-Stake and Staking How Ethereum secures itself without mining: validators stake ETH, are chosen to propose and attest blocks in proportion to their stake, earn rewards, and get slashed for cheating. The Merge, 32 ETH, finality, and staking options explained. 9 min
- 7 Layer-2 Rollups at a Glance How Ethereum scales without giving up security: rollups execute transactions off-chain and post compressed data back to L1, amortizing one L1 cost across many users. Optimistic vs ZK rollups, fraud vs validity proofs, and the trade-offs. 9 min
- 8 Final Exam: The Ethereum Gauntlet A graded, locked capstone exam — 26 one-shot questions spanning every Ethereum lesson: what Ethereum is, the EVM, accounts vs UTXO, gas and EIP-1559 fees, smart contracts and tokens (ERC-20/721), proof-of-stake and staking, and Layer-2 rollups. 16 min
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