What does CNAME stand for?
CNAME stands for Canonical Name. A DNS record that makes one name an alias for another, for example www.example.com pointing to example.com. The alias inherits the target's A/AAAA records; a domain's root (apex) cannot be a CNAME, and a name with a CNAME should carry no other records.
A CNAME record makes one DNS name an alias of another. When a resolver asks for the alias, the answer says that the real (canonical) name is a different one, and the lookup continues with that name until it reaches an address record. Several names can follow a single target this way: change the target's address once and every alias follows. Two rules come with it. A name that has a CNAME should hold no other records, and for that reason the top of a zone, which must carry SOA and NS records, cannot be a CNAME.
CNAME in practice: an example
A company hosts its shop with an outside provider, which says: point shop.example.com at stores.provider.example. The administrator creates a CNAME record for shop with that target. Later the provider moves to new servers and changes its own address records. The shop keeps working without anyone at the company touching DNS.
What CNAME is confused with
CNAME vs A record: what is the difference?
An A record maps a name straight to an IPv4 address. A CNAME maps a name to another name, and the address is found by a second lookup.
CNAME vs MX: what is the difference?
An MX record says which server receives mail for a domain. It has to point at a name with address records: RFC 2181 says the name in an MX record must not be an alias. What MX stands for
Which exams cover CNAME?
CNAME is on the official CompTIA acronym list for two of the four exams covered here.
- Network+ N10-009: 3.0 (Network Operations).
- A+ 220-1201 and 220-1202: 220-1201 2.0 (Networking).
Each number is a CompTIA exam objective and the name in brackets is its domain. The exam puts the term in a scenario; it does not ask you to recite the expansion.
Check yourself: two practice questions
Written by CertSprint for this page. They are not taken from any exam.
1. The name www.example.org must always resolve to wherever host1.cloudprovider.example points, even when that address changes. Which DNS record type does this?
- CNAME
- A
- MX
- TXT
Show the answer
A. CNAME. A CNAME makes www an alias of the provider's name, so it follows any change of the target's address. An A record would have to be edited by hand each time.
2. An administrator tries to add a CNAME record for a name that already has a TXT record, and the DNS server refuses. Why?
- A name with a CNAME cannot hold other record types
- TXT records are obsolete
- CNAME records need a priority value
- The zone has too many records
Show the answer
A. A name with a CNAME cannot hold other record types. RFC 1034 says that if a CNAME is present at a name, no other data should be there. An alias with records of its own would be ambiguous.
Sources: RFC 1034: Domain Names - Concepts and Facilities; RFC 2181: Clarifications to the DNS Specification. The acronym and its expansion come from CompTIA's official acronym lists, linked from each exam glossary above. The explanation, example and questions are CertSprint's own, checked against these sources on 12 November 2026.