This domain name glossary defines the terms domain owners meet when they register, renew, transfer, secure, buy or recover a domain name. Each definition is written in plain English, and where DNAccess has published a full guide, the entry links to it. The glossary is part of our domain name basics section.
Many of these domain terms describe one fact from different angles: the registry holds the record, the registrar holds the account, and whoever controls the registrar account controls the domain. Keep that in mind and most of the vocabulary falls into place.
A
A record
A DNS record that maps a domain or subdomain to an IPv4 address, the numeric address of the server hosting a website. Our guide to nameservers and DNS records covers each record type.
ACPA
The Anticybersquatting Consumer Protection Act, a 1999 United States federal law (15 U.S.C. 1125(d)) that lets a trademark owner sue anyone who registers, traffics in or uses a confusingly similar domain with a bad-faith intent to profit. Unlike the UDRP, it can award money damages. See is cybersquatting illegal.
Aftermarket
The secondary market where already-registered domain names are sold between private parties through marketplaces, brokers and auctions. See buying a domain that is taken.
Auth code (EPP code)
A password unique to one domain, issued by the current registrar, that the gaining registrar must present to transfer the name. Anyone holding the auth code for an unlocked domain can start a transfer. See our guide to domain transfers.
Auto-renew
A registrar setting that renews a domain before it expires by charging the payment method on file. It fails quietly when the card has expired. See our guide to domain renewal.
autoRenewPeriod
An EPP status a gTLD registry applies after automatically renewing an expired domain, typically for up to 45 days. During this window the registrar can still delete the name for a credit, which is when expiry auctions usually run.
B
Backorder
A request placed with a registrar or drop-catching service to try to register a domain the moment it is deleted. It queues an attempt; it does not reserve the name. See domain backorders.
C
ccTLD
A country-code top-level domain, a two-letter extension assigned to a country or territory, such as .uk, .de or .ca, run by a national operator under its own rules. See top-level domains.
clientHold
A registrar-set EPP status that removes a domain from the TLD zone, so it stops resolving and the website and email go dark. It is applied for nonpayment, failed verification or abuse. See domain status codes.
clientTransferProhibited
A registrar-set EPP status that blocks transfers to another registrar. It is what most registrars mean by “locked,” and the owner can usually remove it from the account dashboard.
CNAME
A canonical name record, which makes one hostname an alias of another, such as pointing www.example.com at a hosting provider’s hostname. A CNAME left pointing at an abandoned service can be claimed by someone else.
Cybersquatting
Registering, holding or using a domain that matches or closely resembles someone else’s trademark, in bad faith, to profit from the mark. See our guide to cybersquatting.
D
DMARC
Domain-based Message Authentication, Reporting and Conformance, a policy published as a DNS TXT record that tells receiving mail servers what to do with messages that fail SPF and DKIM checks. A strict policy makes forging your domain in email much harder. See how email domains work.
DNS
The Domain Name System, the distributed directory that translates domain names into IP addresses and other records. Every website visit and email delivery starts with a DNS lookup. See how DNS translates domain names.
DNSSEC
Domain Name System Security Extensions, standards that add cryptographic signatures to DNS records so resolvers can verify an answer has not been forged or altered. See our guide to DNSSEC.
Domain blocking
A registry-level service that prevents others from registering names containing a protected trademark across a group of TLDs, without registering each name. See domain blocking.
Domain parking
Pointing a domain with no website at a placeholder page, often carrying pay-per-click ads or a “for sale” notice. A business domain that suddenly shows a parking page may have expired or been hijacked. See domain parking.
Drop-catching
Registering expired names the instant the registry deletes them, using automated systems connected through many registrar accreditations. Valuable names are often caught within seconds. See re-registered domains.
DS record
A Delegation Signer record, published in the parent zone, that holds a fingerprint of a domain’s DNSSEC key. A stale DS record left after a DNS provider change can make the domain fail to resolve.
E
EPP
The Extensible Provisioning Protocol, the standard language registrars use to create, update, renew, transfer and delete names at the registry. Every change in your account becomes an EPP command. See registrar vs. registry.
Escrow
In a domain sale, a neutral third party that holds the buyer’s payment until the domain is transferred, then releases it to the seller. See how buying domain names works.
Expiry auction
An auction held by a registrar or its partner for a domain that has expired but not been deleted. If the original registrant renews in time, the auction is canceled. See domain auctions.
G
gTLD
A generic top-level domain, an extension not tied to a country, such as .com, .net or .org. gTLD registries and registrars operate under ICANN contracts and policies.
H
Homoglyph
A character that looks like another, such as a Cyrillic “а” in place of a Latin “a,” or “rn” in place of “m.” Homoglyphs are used to build lookalike domains that pass a quick glance.
I
ICANN
The Internet Corporation for Assigned Names and Numbers, the nonprofit that coordinates the domain name system, contracts with gTLD registries, accredits registrars and sets policies such as the Transfer Policy and the UDRP.
IDN
An internationalized domain name, one containing non-ASCII characters such as accented letters or Cyrillic, Arabic or Chinese script. In DNS it is stored in an encoded form beginning with “xn--,” called Punycode.
L
Lookalike domain
A domain built to resemble a real brand’s domain through misspellings, added words, swapped TLDs or homoglyphs, typically for phishing or fraud. See lookalike domains.
M
MX record
A mail exchanger record, naming the server that accepts email for a domain. Change it and incoming mail goes elsewhere, which is why attackers who seize a domain often redirect it.
N
Nameserver
A server that holds a domain’s DNS records and answers queries about them. The nameservers set at the registrar decide who controls website and email routing, so an unexpected nameserver change is an early sign of hijacking. See nameservers and DNS records.
New gTLD
An extension added through ICANN’s New gTLD Program, which opened for applications in 2012, such as .app, .shop, .law and many brand-owned TLDs.
P
pendingDelete
An EPP status applied for five days after the redemption grace period ends. Nobody can restore the domain during this period; when it ends, the name is deleted and released. See the domain expiration lifecycle.
Premium domain
A domain priced above the standard rate, either because the registry designates it premium, often at renewal as well, or because an aftermarket seller prices it for its length, keywords or brand appeal. See domain name value.
Privacy/proxy service
A service that keeps the registrant’s personal details out of the public record. A privacy service masks contact details; a proxy service is listed as registrant on the customer’s behalf. See whether private registration is necessary.
Push (account change)
Moving a domain between accounts at the same registrar. A push needs no auth code and no five-day window, so it is fast and, when misused, hard to reverse. Many vendor disputes begin with one. See recovering a domain held for ransom.
R
RDAP
The Registration Data Access Protocol, the structured lookup system that replaced WHOIS for gTLDs. It returns the registrar, dates, status codes, nameservers and any unredacted contact data. See RDAP vs. WHOIS.
Redemption grace period
A 30-day period after a registrar deletes an expired gTLD domain, during which the original registrant can still restore it, usually for a restoration fee. See expired domain name recovery.
Registrant
The person or organization listed as holder of a domain in the registration data. The registrant of record is the legal holder, whoever manages the account. See domain name ownership.
Registrant contact
The registrant’s recorded name, organization, address, email and phone. The email matters most, because transfer and change confirmations go there. See registrant, admin, tech and billing contacts.
Registrar
A company accredited by ICANN, or by a national operator for ccTLDs, to sell registrations and submit changes to the registry for the registrant. See how domain name registrars work.
Registrar lock
The client-side EPP statuses, usually clientTransferProhibited, clientUpdateProhibited and clientDeleteProhibited, that block transfers and changes. Anyone who signs in to the account can remove them, so the lock is only as strong as the account. See registrar account security.
Registry
The organization that operates a TLD and keeps the authoritative database and zone file for it, such as Verisign for .com and .net. It accepts changes only from the sponsoring registrar.
Registry lock
A registry-level hold, using server-side transfer, update and delete prohibitions, that blocks changes until the registrar verifies the request with the owner out of band. A stolen password alone cannot lift it. See registry lock.
Renewal
Extending a registration for another term. gTLD names renew in one-year increments, with no more than ten years remaining on the registration at once.
Reseller
A web host, website builder or IT provider that sells registrations under another registrar’s accreditation. The accredited registrar may never appear on the invoice, which can slow a recovery.
Reverse domain name hijacking
Using the UDRP in bad faith to try to take a domain from a legitimate registrant. Panels can make a formal finding of it against the complainant. See reverse domain name hijacking.
S
Second-level domain
The label just left of the TLD, such as “example” in example.com. With the TLD, it forms the registered name. See what is a domain name.
Subdomain
A label added to the left of a registered domain, such as shop in shop.example.com. Subdomains are created in the domain’s own DNS, not registered separately.
T
TDRP
The Transfer Dispute Resolution Policy, ICANN’s procedure for registrar-to-registrar disputes over a transfer. Only a registrar can file, within twelve months, and the panel decides only whether policy was followed. See the step-by-step stolen domain recovery guide.
TEAC
The Transfer Emergency Action Contact, an urgent channel every ICANN-accredited registrar must maintain for transfer emergencies such as a hijacking. A human must respond within four hours, though resolution may take longer. See stolen domain name recovery.
TLD
A top-level domain, the extension after the final dot, such as .com, .org or .uk. TLDs divide into gTLDs and ccTLDs.
TMCH
The Trademark Clearinghouse, a repository of verified trademarks that supports sunrise periods (early registration for trademark holders) and claims notices in new gTLDs. See online brand protection.
Transfer
Moving a domain to a different registrar. The gaining registrar submits the auth code, the losing registrar has five days to object, and the move usually adds a year to the registration.
Transfer lock (60-day)
A period, generally 60 days after registration, an inter-registrar transfer or a change of registrant, during which the domain cannot move to another registrar under ICANN’s Transfer Policy. It also slows thieves trying to move a name twice. See domain status codes.
TTL
Time to live, the number of seconds resolvers may cache a DNS record. A long TTL means a wrong or malicious change can linger after it is fixed.
TURF
The Transfer Undo Request Form, a sworn, usually notarized request submitted through a registrar to reverse an unauthorized transfer. With a cooperative gaining registrar it is often the fastest path. See the TURF explainer.
Typosquatting
Registering misspellings of a popular domain to capture people who mistype it, usually for ad revenue, phishing or malware. See typosquatting.
U
UDRP
The Uniform Domain-Name Dispute-Resolution Policy, the ICANN procedure through which a trademark owner can have a bad-faith domain transferred or canceled by a panel rather than a court. See our UDRP guide.
URS
The Uniform Rapid Suspension System, a faster procedure, mainly for new gTLDs, that suspends a clearly infringing domain rather than transferring it. See UDRP vs. URS vs. ACPA.
W
WHOIS
The legacy protocol for looking up registration records. ICANN set 28 January 2025 as the sunset date for gTLD registrars’ WHOIS obligations in favor of RDAP, according to ICANN’s notice on the 2013 RAA amendment, though the word is still used for any lookup. See what WHOIS is.
WHOIS history
Archived snapshots of a domain’s past registration records, often from before privacy redaction. It is central evidence in ownership disputes and theft cases. See WHOIS history.
Z
Zone file
A file of DNS records for a zone. A TLD zone file lists every delegated domain and its nameservers; a domain’s own zone holds its A, MX, CNAME and other records.
How DNAccess helps
Every term in this glossary bears on one question: who controls a domain name, and how that control is protected, transferred or lost. Our domain name management service keeps registrant details, renewals, locks and DNS in order for every name a business holds. If a term here describes something that has already gone wrong with your domain, contact us.