ERC-20: Token Standard
ERC-20 is the most widely deployed standard in the Ethereum ecosystem. Every DeFi integration, exchange, and wallet interacts with ERC-20 tokens constantly.
What It Defines
Defines the standard interface for fungible tokens on EVM chains: totalSupply, balanceOf, transfer, transferFrom, approve, allowance events. Every fungible token (USDC, WETH, DAI, etc.) implements this interface.
Canonical (Normative)
Convenient (Practical)
The Ethereum community's open process for proposing changes to the protocol. EIPs cover core protocol changes; ERCs (Ethereum Request for Comments) cover application-layer standards like token interfaces.
Related Specs
NFTs, digital ownership, gaming assets, and on-chain certificates all use ERC-721. The standard that launched the NFT market.
More gas-efficient than deploying separate ERC-20 + ERC-721 contracts. Standard for gaming, semi-fungible assets, and multi-edition NFTs.
All Ethereum JSON-RPC APIs (Infura, Alchemy, local nodes, MetaMask) use JSON-RPC 2.0. You need to know the protocol to interact with EVM chains.