Glossary of domain terms

The vocabulary of domain names is small but unforgiving, and most of it appears for the first time in an email that needs answering. These are the terms that matter.

The words below turn up in renewal notices, transfer confirmations and support tickets, often without explanation. Terms are listed alphabetically, and the fuller treatment of most of them sits in the basics section.

Term	Meaning
Aftermarket	The trade in names that are already registered, whether through marketplaces, brokers or private sales, as opposed to registering a name that is free.
Authorisation code	A code issued by the current registrar that authorises a transfer to another registrar. Also called an auth code, EPP code or transfer key.
Automatic renewal	A registrar setting that attempts payment of the renewal without anyone acting. It fails silently when the stored payment method has expired.
Broker	An intermediary who negotiates the purchase of a name on behalf of a buyer, usually paid a success fee if the acquisition completes.
ccTLD	A country code top level domain, meaning a two letter extension tied to a territory, such as .nl or .be. Some carry eligibility conditions.
DNS	The Domain Name System, the distributed directory that translates names into the addresses machines use to reach each other.
Domain name	The registered entry in a registry that gives an organisation an address of its own. A registration is a lease for a term, not a permanent purchase.
Drop	The moment a deleted registration is released and becomes available to register again. Popular names are frequently taken within seconds.
Escrow	A neutral third party that holds the buyer's payment until the name has been transferred, then releases it to the seller.
Expiry date	The date the current registration term ends. It is the start of the recovery sequence, not the point at which the name is lost.
Extension	The final part of an address, such as .org or .com. The formal term is top level domain.
Grace period	A window after expiry during which the registrar generally allows the previous registrant to renew at the ordinary price. Its length varies by registrar and extension.
gTLD	A generic top level domain, meaning an extension not tied to a country, including .org, .com, .net and the many newer endings.
Hosting	The server space where a website's files live. It is a separate service from the domain registration and is frequently bought from a different supplier.
ICANN	The body that coordinates the domain name system and sets the rules registrars of generic extensions have to follow.
Lock	A status that blocks a transfer. Registrars lock names by default, and a lock also applies for a period after a transfer or a change of registrant.
MX record	The DNS entry that says where mail for the domain should be delivered. Editing DNS without preserving it is the usual cause of mail suddenly failing.
Nameserver	The server that answers DNS queries for a domain. Pointing a name at different nameservers hands control of all its records to whoever runs them.
Parking	Pointing a registered name at a placeholder page, often carrying advertising or a for sale notice, rather than at a real website.
Pending delete	The final status before deletion, during which the registration cannot be restored, renewed, transferred or registered by anybody.
Privacy service	A registrar service that replaces the registrant's contact details in public records with forwarding details. Personal data is now withheld by default in most cases.
Propagation	The delay between changing a DNS record and the change being visible everywhere, caused by caching rather than by anything travelling.
RDAP	The structured protocol that has replaced WHOIS for registration lookups, returning consistent records and applying access rules to personal data.
Redemption period	A registry stage after deletion during which only the former registrant, acting through the original registrar, can restore the name, for a restore fee.
Registrant	The party named in the registry as holding the registration. The registrant is who the registrar takes instructions from, whoever pays the invoice.
Registrar	The company through which a name is registered and renewed, and which holds the account controlling it.
Registry	The organisation operating an extension and maintaining the authoritative database of every name under it.
Renewal	Payment extending the registration for a further term. A registration is never permanent and always has a next renewal date.
Transfer	Moving a registration from one registrar to another, using an authorisation code and confirmed from the contact address on the record.
UDRP	The dispute procedure covering generic extensions, under which a trademark holder can seek transfer or cancellation of an abusive registration.
WHOIS	The older lookup service for registration data, now largely superseded and heavily redacted where personal information is involved.