blockmindset
Lesson 4 of 514 min

Token Standards

Token standards define shared interfaces so wallets and protocols can interact with assets consistently.

Why this matters

ERC-20, ERC-721, and ERC-1155 explain fungible tokens, NFTs, approvals, marketplaces, and composability.

1

The Intuition

A standard is a common language. Wallets can support many assets because those assets expose familiar functions and events.

2

See it concretely

Concrete example

USB works because devices agree on a connector. ERC standards work because token contracts agree on functions and events.

3
⚠

Tempting — but wrong

4

The precise version

ERC-20 defines balances, transfers, approvals, allowances, and transferFrom for fungible tokens. ERC-721 defines ownership and transfer for unique token IDs. ERC-1155 supports multiple token types in one contract. Approval flows enable composability but can expose users to allowance-drain risk.

interoperability = sharedInterface + consistentEvents + ecosystemAdoption

Check your understanding

Why can wallets display many ERC-20 tokens?

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Why are unlimited approvals risky?

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Before moving on
  • Compare ERC-20, ERC-721, and ERC-1155.
  • Explain approve and transferFrom.
  • Explain why events matter for indexing.
  • Separate interface compliance from trustworthiness.
?Checkpoint

What does ERC-20 primarily provide?

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