Level 2 · Module 2.2

Ethereum — The World Computer

Bitcoin proved you could have money without banks. Ethereum asked the next question: what if you could have contracts, applications, and organisations without lawyers, companies, or governments?

⏱ 12 min read 🟡 Intermediate 📖 5 sections

01 Origin: The 19-Year-Old Visionary

In 2013, Vitalik Buterin — a 19-year-old Bitcoin developer — proposed extending blockchain beyond currency. His whitepaper described a platform where developers could build any application on top of a blockchain. The idea: a programmable blockchain.

In 2014 they raised $18M in a crowdsale. In 2015 the mainnet launched. In 2022 — after years of work — Ethereum switched from Proof of Work to Proof of Stake in an upgrade called "The Merge", cutting energy consumption by 99.95% overnight.

02 Smart Contracts: Code as Law

This is Ethereum's core innovation. A smart contract is a program stored on the blockchain that executes automatically when predetermined conditions are met. No human needs to be involved.

LIVES ON CHAIN

Once deployed, the code is immutable and transparent. Anyone can read exactly what it does.

EXECUTES AUTOMATICALLY

If conditions are met, execution is guaranteed — no intermediary, no approval required, no possibility of refusal.

TRUSTLESS

You don't need to trust the person you're transacting with. You only need to trust the code — which you can read and verify yourself.

UNSTOPPABLE

Not even the original developer can stop a deployed contract. This is powerful — and also means bugs are permanent.

Analogy — The Infallible Vending Machine

A traditional contract requires lawyers, signatures, courts, and trust. A smart contract is like a vending machine: insert the coin, press the button, the product comes out. No cashier. No negotiation. No "the computer says no." The code does exactly what it says it will do — every single time.

03 Gas Fees — The Cost of Computation

Every operation on Ethereum costs gas — a unit measuring computational work. Gas is paid in ETH, and its price fluctuates with network demand.

WHY FEES EXIST

Without fees, someone could run an infinite loop and paralyse the entire network for free. Fees make spam economically irrational.

EIP-1559 (2021)

A major upgrade: the base fee is now burned (permanently destroyed). During high activity this makes ETH deflationary — fewer ETH exist after each transaction.

WHEN FEES ARE HIGH

During NFT drops, DeFi events, or market crashes, fees can exceed $100 for a simple swap. This is why Layer 2 networks (Arbitrum, Base, Optimism) exist — same security, 100x cheaper.

04 The Ethereum Ecosystem

Ethereum hosts the largest ecosystem of decentralised applications ever built:

DeFi

Uniswap, Aave, Compound, MakerDAO — lending, borrowing, and trading with billions of dollars, no bank account required.

NFTs

OpenSea, Blur — the majority of historically significant NFT collections were born on Ethereum.

STABLECOINS

USDC, USDT, DAI — the most important dollar-pegged assets run primarily on Ethereum.

LAYER 2s

Arbitrum, Optimism, Base, zkSync — Ethereum's scaling ecosystem is the most developed in the industry. Most new dApps launch on L2 first.

05 Ethereum vs Bitcoin

A common mistake is framing these two as competitors. They're not:

Dimension	Bitcoin	Ethereum
Primary purpose	Store of value	Programmable platform
Consensus	Proof of Work	Proof of Stake
Smart contracts	Limited	Full (Turing-complete)
Supply	21M cap (fixed)	No hard cap (deflationary at times)
Philosophy	Conservative, secure	Innovative, composable
Speed	~7 TPS	~30 TPS (L2s: thousands)

The right question is not "Bitcoin or Ethereum?" — it's "what are you trying to do?" Bitcoin is the most secure store of value ever created. Ethereum is the most powerful programmable network ever built. Both have their place.

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