A .eth name is the native top-level domain of ENS, secured on the Ethereum blockchain. Names ending in .eth can be used as wallets, websites, and identity. Ownership is held as an ERC-721 token, so a .eth name can be transferred or sold like any other on-chain asset.

What is an ENS registrar?

A registrar is the smart contract that controls the registration and renewal of ENS names. It defines how long a name is valid, what happens when it expires, and enforces pricing that scales with name length. Once a name is registered, the registrar can only affect whether it stays registered, not the records the owner sets.

What is an ENS resolver?

A resolver is a smart contract that translates an ENS name into the data it points to, such as an ETH address, an avatar, or a content hash. Each name points to its own resolver through the registry, and multiple records can be set per name. Owners can change which resolver a name uses at any time.

What is an ENS subname?

A subname is a name that lives under a parent ENS name, such as team.project.eth under project.eth. The parent owner can create as many subnames as they want, each with its own records and owner. Burning the PARENT_CANNOT_CONTROL fuse makes a subname fully independent of the parent.

ENS Glossary

Q: What is ENS?

ENS (Ethereum Name Service) is the decentralized naming system on Ethereum. It maps human-readable names like alice.eth to machine-readable identifiers such as wallet addresses, content hashes, and metadata. It runs on-chain through a registry that records ownership and resolvers that store each name's data.

Clear, jargon-free definitions of the terms you will meet in the ENS ecosystem. Search or browse.

ENS (Ethereum Name Service)

The decentralized naming system on Ethereum. It maps human-readable names like alice.eth to machine-readable identifiers such as wallet addresses, content hashes, and metadata. ENS is made up of two contracts at its core: the registry, which records which account owns each name, and resolvers, which store the data each name points to. Because it lives on-chain, ENS does not depend on a single company or server to keep names working. A name can hold an ETH address, other cryptocurrency addresses, a website, an avatar, and arbitrary text records at the same time.

.eth

The native top-level domain of ENS. Names ending in .eth are secured on the Ethereum blockchain and can be used as wallets, websites, and identity. It is a real top-level domain secured by the .eth registrar, and it is the only TLD that ENS itself issues directly without relying on DNS. Ownership of a .eth name is held as an ERC-721 token, so it can be transferred or sold like any other on-chain asset. It can also be imported into the traditional DNS namespace through Name Wrapper, which lets a .eth name carry DNSSEC records.

Registrar

The smart contract that controls the registration and renewal of ENS names. It defines how long a name is valid and what happens when it expires. The .eth registrar also enforces the pricing rules, charging per year based on name length, and applies a temporary premium to recently expired names. It works alongside the registry, which stores ownership, while the registrar handles the business logic of buying and renewing. Once a name is registered, the registrar can only affect whether it stays registered, not the records the owner sets.

Resolver

A smart contract that translates an ENS name into the data it points to, such as an ETH address, an avatar, or a content hash. Multiple records can be set per name. Each name points to its own resolver through the registry, and an owner can change which resolver is used at any time. Records are stored under keys defined by EIP-2304 and related standards, covering addresses for many chains, text records, and content hashes. Resolvers can also answer backwards, turning an address back into its primary name.

Registration

The process of claiming an available ENS name for a set period (typically one year, renewable). Registration requires a fee that scales with name length.

Renewal

Extending the validity of an ENS name before it expires. Names do not renew automatically; you must renew to keep ownership.

Grace Period

A window after a name expires during which the previous owner can still renew it, typically 90 days. After this, the name becomes available for others to register.

Subname

A name that lives under a parent ENS name, such as team.project.eth under project.eth. Subnames enable hierarchical ownership and flexible identity. The parent owner can create as many subnames as they want, and each one can have its own resolver, records, and even its own owner. To make a subname fully independent, the parent must burn the PARENT_CANNOT_CONTROL fuse and set an expiry, after which the parent can no longer take it back. This makes subnames useful for issuing names to teams, communities, and users without giving away the parent name.

ENSv2

The next major upgrade to ENS. It introduces hierarchical name management, lower-cost operations, and a more flexible architecture for subnames and ownership. In ENSv2, each name gets its own on-chain registry, so subname registrations happen in a local registry rather than needing to touch a single global contract. This change is designed to make registering and managing subnames cheaper and to let names be deployed on other chains while still resolving from Ethereum. Migration from ENSv1 is planned to preserve existing names and records.

Namechain

The implementation name for the ENSv2 protocol upgrade. It lives on Ethereum Mainnet, where all ENS resolution begins.

CCIP-Read

Chain-agnostic Cross-Chain Interoperability Protocol. It allows resolvers to read data from any chain, enabling cross-chain name resolution.

Universal Resolver

A public resolver that supports many record types and uses CCIP-Read to resolve names across chains. Part of ENS infrastructure.

Seaport

A marketplace protocol on Ethereum used for buying and selling NFTs, including ENS names. It enables peer-to-peer trading through signed messages.

Primary Name

The ENS name a wallet designates as its primary identifier. It is used to display the name instead of the raw address in many apps.

Multi-sig (Multisig)

A wallet that requires multiple signatures to execute a transaction. Often used by DAOs and projects to secure shared funds.

L2 (Layer 2)

A scaling solution built on top of Ethereum that processes transactions faster and cheaper. ENS name resolution is moving to support L2s.

Offchain Resolution

Resolving an ENS name using data stored off the main Ethereum chain, typically via CCIP-Read, enabling faster and cheaper lookups.