Coins, Tokens & Crypto Assets
A standard says how to talk to a token. Never whether to trust it.
Without shared rules, every wallet and every exchange would have to integrate every project one by one. Token standards remove that work — and removing it says nothing at all about the token behind the interface.
The problem
Three tokens. One wallet. Plug them in.
The wallet only knows the standard. It checks three calls and decides what it can show you. Watch which token it cannot display — then look closely at the one it displays perfectly.
The wallet's compatibility check
ILLUSTRATIVEThree tokens are waiting. Press Connect all three and watch what the wallet can do with each one.
A standard is an interface, not a verdict. It fixes how a token is addressed technically — how it is transferred, how a balance is read, how the total supply is checked — so one wallet can work with many tokens to the same pattern. Token B follows its own rules, so nothing generic can display it: without shared rules every wallet and exchange would have to integrate every project separately, which is unaffordable effort and a pile of isolated islands. That is the benefit, and it is the whole benefit. Now ask the other question by hand.
Token C implements the standard flawlessly and is a pure scam. Both are true at once, because the standard governs only the technical interface — function names, no value judgement. A fraud token with clean code is still fraud. Standards check the technology, never the intent, and they hand out no quality guarantee. Everything the wallet knew about Token C came from the interface; the fact that mattered had to come from somewhere the standard cannot reach.
The definition
Three things a standard is, and one it isn't.
Tap each card for what sits behind it.
Hands on
Fungible, or one of a kind?
Two standards cover almost everything you will meet. Tap an example to see which one it belongs to — and what decides it.
Stablecoin unit
ERC-20ERC-20 is the ground under stablecoins, governance and utility tokens. ERC-721 is the ground under NFTs.
The bridge
Three things standards created — and one they never did.
Whole ecosystems grew on the first three. The fourth is the line the standard cannot cross.
So if the interface cannot tell you whether a token is worth anything, something else has to be read instead. The next lesson opens the figures a project publishes about itself — supply, issuance, distribution — and works through what each of them actually means.
Check yourself
Five questions.
Answers come straight from this lesson. Submitting completes it.