An EIP (Ethereum Improvement Proposal) is a formal document that describes proposed changes, new features, or standards for the Ethereum network. EIPs are the primary mechanism through which the Ethereum community discusses and agrees on protocol upgrades.
Types of EIPs
Standards Track: Changes affecting most or all Ethereum implementations — core protocol changes, networking, interface, or ERC standards.
Meta: Process changes or guidelines for the Ethereum community.
Informational: General guidelines or design issues.
Notable EIPs
EIP-1559: Introduced fee burning and a base fee mechanism, fundamentally changing Ethereum's fee market and making ETH potentially deflationary.
EIP-4844: "Proto-danksharding" — introduced blob transactions to dramatically reduce Layer 2 data costs.
EIP-721: Defined the NFT standard.
EIP-20 (ERC-20): Defined the fungible token standard used by thousands of tokens.
Process
Anyone can propose an EIP. It goes through stages: Draft, Review, Last Call, and Final. Core EIPs require extensive community discussion and consensus before being implemented in a network upgrade.