How Token Standards Work: ERC-20, ERC-721 and Beyond
The templates that let wallets, exchanges, and dApps handle tokens uniformly.
A token standard is a shared interface — a set of functions a smart contract must expose so that other software knows how to interact with it. Standards are what make thousands of different tokens work in the same wallet with no per-token code.
ERC-20 is the standard for fungible tokens on Ethereum. Every ERC-20 exposes the same core functions: balanceOf, transfer, approve, and a few others. Any wallet or exchange that speaks ERC-20 can handle any ERC-20 token.
ERC-721 is the standard for non-fungible tokens (NFTs). Each token has a unique ID and is tracked individually. ERC-1155 is a hybrid that allows a single contract to manage many token types at once — useful for games and collectibles.
Other ecosystems have their own equivalents — SPL on Solana, TRC-20 on Tron, and so on. The principle is the same everywhere: a common interface is what turns a protocol into a platform.