Chapter 10

Token Standards

Ethereum token standards are shared interfaces. They let wallets, exchanges, marketplaces, and vault aggregators integrate thousands of assets without custom code for each one. When a token follows the standard, the ecosystem can treat it as a familiar object instead of an unknown contract.

Most user-facing Ethereum assets fall into one of these formats, each solving a different ownership pattern.

Four standards you see constantly

Standard	What it represents	Why it matters
ERC-20	Fungible balances	Powers stablecoins, governance, and DeFi liquidity
ERC-721	Unique token IDs	Best fit for one-of-one NFTs and identity objects
ERC-1155	Many token types in one contract	Cheaper batch transfers for games and editions
ERC-4626	Tokenized vault shares	Normalizes yield vault deposits, shares, and redemptions

The point of a standard is not elegance for its own sake; it is portability, so assets and apps can plug into the same tooling.

ERC-20 is the language of fungible value on Ethereum. If you have ever approved USDC for a swap, staked a governance token, or tracked a treasury balance, you were relying on the same small set of methods:transfer, approve, and balanceOf.

ERC-721 and ERC-1155 both serve NFT-style use cases, but the tradeoff is granularity versus efficiency. ERC-721 treats every token as fully distinct, while ERC-1155 lets one contract manage multiple item types and move them in batches. ERC-4626 extends the standardization idea into DeFi by giving yield vaults a predictable interface that other protocols can compose around.