What Is Cryptocurrency?

Cryptocurrency is a digital asset controlled by cryptographic keys and usually settled on a blockchain. What matters for users is what the asset does, where it settles, and who controls the keys.

In Crypto Fundamentals, cryptocurrency is a foundation the later lessons build on, so it is worth getting exactly right.

Coins native to a chain pay fees or secure the network.

Tokens are issued by smart contracts or protocols on top of a chain.

Market value comes from supply, demand, liquidity, utility, and belief in the network.

Strip it back and the mechanics all point to one fact: crypto is digital money secured by cryptography on a blockchain.

ETH can be used to pay gas on Ethereum, while a token such as USDC can move on Ethereum but follows a separate issuer and reserve model.

The value here is the checklist hiding inside the cryptocurrency example, not the specific names or numbers used.

Watch the failure condition in any cryptocurrency example; that is usually where money is won or lost, not in the happy path.

Seeing a balance in an app does not always mean you hold the on-chain asset yourself. The app may be showing a custodial claim.

Before acting on cryptocurrency, name the one thing that would have to be true, then confirm it.

With cryptocurrency, the real cost is rarely the first error — it is acting on it with size before checking the assumption.

Crypto risk includes volatility, smart-contract bugs, exchange failure, chain congestion, and irreversible transfers to wrong addresses.

Write the single cryptocurrency failure mode you would watch for, then size the decision around that rather than the upside.

For cryptocurrency, reversible, small, and verifiable beats large and irreversible whenever the picture is still unclear.

Don't leave What Is Cryptocurrency? as theory. Run it against a concrete Crypto Fundamentals situation you can actually inspect.

Aim for cryptocurrency judgement you can defend, not a tidy summary you can merely recite.