DNS records are the individual lines of instruction stored for a domain. One says which server shows the website, another says where email goes, another proves to Google that you own the name. Together they make up the domain's zone, and editing them is how you connect a domain to anything.
What every record contains
Each record has four main parts: a name (the host it applies to, where @ means the bare domain), a type, a value, and a TTL saying how many seconds resolvers may cache it. A zone can hold many records with the same name as long as the types allow it.
The record types you will actually meet
- A: maps a name to an IPv4 address such as
203.0.113.10. - AAAA: the same job for an IPv6 address.
- CNAME: makes one name an alias of another hostname.
- MX: names the mail servers that accept email for the domain.
- TXT: free text, used for SPF, DKIM, DMARC and ownership checks.
- NS: lists the nameservers responsible for the zone.
- CAA: limits which certificate authorities may issue SSL certificates for the domain.
- SOA: zone housekeeping data, created automatically and rarely edited.
Example: a zone for a small law firm
A firm's zone might contain an A record for @ pointing at its website host, a CNAME for www pointing at the bare domain or the host's hostname, two MX records for Microsoft 365, a TXT record with its SPF policy, a CNAME for DKIM signing, a TXT record at _dmarc, and a TXT verification string for Google Search Console. Eight or so lines run the entire online presence.
When you will edit records
Hosting providers, email services and marketing tools all give setup instructions in the form "add this record". Copy the type, name and value exactly. You do not need to understand every record to follow those steps, but you should know which provider hosts your zone, because records only take effect there.
Mistakes when editing records
- Two A records by accident. Leaving the old host's IP alongside the new one makes visitors land on either at random.
- Putting the domain in the name field. Many panels append it for you, creating a doubled hostname.
- Adding a second SPF TXT record. A domain may have only one; merge them instead.
- Not saving a copy before big changes. Export or screenshot the zone so you can restore anything you break.
Related terms
- DNS: the system that serves these records.
- CNAME: the alias record.
- MX record: the email routing record.
- TXT record: the record for verification and email security.