# ERC-20

> The fungible-token standard on Ethereum — the interface (transfer, balanceOf, approve) that makes any token work with any wallet or exchange.

Before ERC-20, every token invented its own interface and every wallet needed bespoke support. The standard fixed a handful of functions and events — transfer, approve, balanceOf — and an ecosystem formed: any conforming token is listable, swappable and walletable on day one.

The sharp edge is 'approve': it lets another contract spend from your balance, up to the amount you allow — and unlimited approvals, granted once and forgotten, are how most drained wallets are drained. 'Revoke what you no longer use' is basic wallet hygiene, the way revoking API keys is.

## Related terms

- https://dfieldsolutions.com/en/glossary/erc-721.md
- https://dfieldsolutions.com/en/glossary/smart-contract.md
- https://dfieldsolutions.com/en/glossary/spl-token.md

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Source: https://dfieldsolutions.com/en/glossary/erc-20
DField Solutions — Dunakeszi, Hungary — dezso@dfieldsolutions.com
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