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Lesson 12 of 73
intermediate6 minQuiz included

Cryptocurrency Deep Dive

What Is Ethereum?

Ethereum, stablecoins, exchange mechanics, and self-custody.

Updated Oct 21, 2026GaiaEx Academy Editorial

In this lesson

  • Ethereum's programmable design
  • What gas pays for

Key takeaways

  1. 1Ethereum is a 'world computer' running smart contracts
  2. 2Gas is the fee to execute transactions and code
  3. 3Programmability is what sets it apart from Bitcoin

Lesson summary

Ethereum is a programmable settlement network.

Mental model

What Is Ethereum?, without the jargon

Ethereum is a programmable settlement network. ETH is the asset used to pay for computation, but the larger idea is that contracts can define shared financial logic.

  • Ethereum's programmable design
  • What gas pays for

Mechanics

How to reason about Ethereum

Smart contracts run on the Ethereum Virtual Machine.

Gas prices the computation and storage a transaction consumes.

Validators include transactions and finalize the chain under Proof of Stake.

  • Ethereum is a 'world computer' running smart contracts
  • Gas is the fee to execute transactions and code
  • Programmability is what sets it apart from Bitcoin

Example

Ethereum in a real decision

A user swapping tokens on a DEX pays gas in ETH even if the swap involves two other tokens, because Ethereum is executing the contract logic.

RememberDecision rule: Analyze Ethereum as infrastructure plus asset, not as one isolated token.

Common mistakes

What to unlearn about Ethereum

Ethereum is not only a coin. Judging it only by ETH price misses stablecoins, DeFi, NFTs, rollups, and settlement demand built on top.

Risk notes

Staying safe around Ethereum

High gas, contract bugs, validator centralization, and Layer-2 bridge assumptions affect Ethereum users differently.

  • Explain what gas pays for.
  • Connect ETH to contract execution.
  • Identify one Ethereum ecosystem dependency.

Practice

Make Ethereum stick

  • Explain what gas pays for.
  • Connect ETH to contract execution.
  • Identify one Ethereum ecosystem dependency.

Review

Key terms

Bitcoin (BTC)
The first cryptocurrency, launched in 2009 — a decentralized, hard-capped (21M) digital money.
Custody
Who controls the private keys. Custodial = a third party holds them; non-custodial = you do.
DeFi
Decentralized Finance — permissionless, composable financial services built on smart contracts.
Ethereum (ETH)
A programmable blockchain — a 'world computer' that runs smart contracts and dApps.
Layer 2
A protocol built atop a Layer 1 to scale it — processing transactions off-chain then settling on-chain.

Source notes

Editorial references

These references are starting points for verifying the mechanisms, risk checks, and product context behind this lesson.

bitcoin.orgBitcoin whitepaperPrimary reference for peer-to-peer electronic cash, proof-of-work, and double-spending.ethereum.orgEthereum developer documentationProtocol-level documentation for accounts, transactions, blocks, clients, and the Ethereum stack.ethereum.orgConsensus mechanismsReference for how distributed networks agree on valid state and why incentives matter.ethereum.orgEthereum walletsReference for wallet responsibilities, keys, and user-side custody.

Before you continue

Can you do these?

  • Explain what gas pays for.
  • Connect ETH to contract execution.
  • Identify one Ethereum ecosystem dependency.

Related learning

Keep reading

Next lessonEthereum vs Bitcoin: Key Differences ExplainedIntermediate Track course pathPrevious lessonWeb3 Data OwnershipIntermediate Track course pathTrack overviewIntermediate Track73 lessonsGlossaryBitcoin (BTC) and related terms5 terms from this lesson

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