What Is ENS? How Ethereum Name Service Domains Work

The Ethereum Name Service (ENS) is a decentralized naming system that lets users register human-readable ".eth" domains as NFTs on Ethereum, which then resolve to wallet addresses, decentralized website content, and other metadata records instead of requiring people to share long hexadecimal addresses. It's the most widely adopted implementation of the broader concept covered in our NFT domain names explainer.

ENS domains are registered through a smart contract system and, since a 2019 protocol update, represented as ERC-721 NFTs — meaning a ".eth" name is a genuine, transferable, tradeable token that its holder fully controls, not a rented listing from a centralized registrar.

How registration and renewal work

Registering an ENS name involves choosing an available name, paying a registration fee (priced partly by character length, with shorter names costing significantly more per year), and completing the registration through the ENS smart contracts. Registration is time-limited — commonly registered in one-year increments — and requires renewal payments to keep the domain active. If a registration lapses without renewal, there's a grace period, after which the name becomes available for anyone else to register.

This differs from some newer name systems on other chains that use one-time, permanent registration; ENS's renewal-based model funds ongoing protocol development but does mean forgetting to renew carries real consequences.

Resolver records: what a name can point to

Once registered, an ENS name is configured through a resolver contract that stores its actual records. The most common record type is a cryptocurrency address — commonly the owner's Ethereum address, but resolvers can also store addresses for other chains, so a single ".eth" name can theoretically resolve to different addresses depending on which network a sender is using. Beyond addresses, resolver records can store an avatar image, a content hash pointing to a decentralized website (letting ".eth" names double as web addresses for IPFS-hosted sites), and social/contact metadata.

Record type	What it stores	Common use
Address record	Wallet address for a given chain	Receiving payments without sharing raw addresses
Content hash	IPFS/Arweave content reference	Hosting a decentralized website at a .eth name
Text records	Avatar, social handles, description	Profile-style identity display in wallets and apps
Reverse record	Maps an address back to its primary name	Displaying "name.eth" instead of an address in apps

Subdomains and organizational use

ENS supports subdomains (like "team.projectname.eth"), which the owner of the parent domain can create and assign independently, often used by organizations, DAOs (see our DAO explainer), or projects to issue branded addresses to members or services without each needing a separate top-level registration.

Security and phishing risks

Because ENS names resolve to addresses, they inherit the same risks covered in our NFT domain names piece: a compromised owner account can redirect a resolver's records, and lookalike names (using similar-looking characters or slight misspellings) are a known phishing vector. Confirming the actual resolved address independently before sending significant funds — rather than trusting a displayed name alone — remains good practice, and applies the same wallet security principles used for any other crypto asset.

Governance and the ENS DAO

ENS transitioned to community governance through a DAO structure, with an associated governance token used for voting on protocol parameters, treasury allocation, and future development priorities. This mirrors the governance patterns used across many Web3 protocols; see our DAO governance models comparison for how token-based voting systems like this generally work.

Cost structure and premium names

ENS registration cost scales inversely with name length — shorter names cost substantially more per year to register than longer ones, reflecting both higher demand for short, memorable names and a deliberate design choice to discourage squatting on the most desirable short strings. Beyond the base annual registration fee, some particularly short or historically significant names have also traded on the secondary market for large sums, similar to premium domain name sales in the traditional web, since a scarce, memorable ENS name can carry standalone collectible and branding value independent of its practical addressing utility.

Integration across wallets and applications

Part of ENS's practical value comes from broad adoption across the wallet and application ecosystem — many popular wallets automatically resolve and display ENS names in place of raw addresses wherever a user has one set as their primary name, and a growing number of applications beyond wallets (social platforms, marketplaces) support looking up and displaying ENS identities as well. This network effect matters: a naming system with strong technical design but minimal integration into the tools people actually use provides far less real-world convenience than one that's broadly recognized and automatically resolved across the ecosystem.

Bottom line

ENS turns memorable ".eth" names into ownable, tradeable NFTs that resolve to wallet addresses and other on-chain metadata, offering a real usability improvement over raw addresses while requiring attention to renewal deadlines and resolver security. Check the glossary entry on NFTs for the underlying token mechanics, and always verify a resolved address independently before trusting a name alone for a high-value transfer.