// GLOSSARY -- BLOCKCHAIN & CRYPTO FUNDAMENTALS
What is ENS (Ethereum Name Service)?
Ethereum Name Service (ENS) is a decentralized naming system that maps human-readable names (like vitalik.eth) to Ethereum addresses — replacing complex hex addresses with memorable identifiers.
WHY IT MATTERS
ENS is the DNS of Web3. Instead of sending tokens to 0x1234...5678, you send to alice.eth. The ENS smart contracts resolve the name to the address on-chain, making crypto more usable and less error-prone.
ENS names are NFTs (ERC-721 tokens) owned by the registrant. They can point to: Ethereum addresses, other crypto addresses, content hashes (IPFS websites), text records (social profiles), and more.
ENS has become identity infrastructure for Web3 — profiles, login systems, and social apps use ENS names as the default identifier.
FREQUENTLY ASKED QUESTIONS
How much do ENS names cost?
3-character names: $640/year. 4-character: $160/year. 5+ characters: $5/year. Premium/desirable names may cost more. Registration requires gas for the on-chain transaction.
Can I use ENS outside Ethereum?
ENS is expanding to L2s and other chains. Some wallets and services resolve ENS names for non-Ethereum addresses. Cross-chain ENS is an active area of development.
Is ENS decentralized?
The smart contracts are decentralized. The ENS DAO governs the protocol. The .eth registrar is on-chain. However, DNS integration and some operational aspects involve centralized components.