What is the difference between an A record and a CNAME?

An A record points a hostname directly to an IPv4 address, while a CNAME points one name to another name as an alias. You cannot put a CNAME at the zone apex, and a name with a CNAME should not also have other records.

How do SPF, DKIM, and DMARC relate to DNS?

All three are email-authentication mechanisms published as TXT records. SPF lists allowed sending servers, DKIM publishes a signing public key, and DMARC sets a policy that ties SPF and DKIM results to your domain.

What does the priority number in an MX record mean?

Each MX record has a preference value, and mail servers try the lowest number first. Equal values are load-balanced. So MX 10 is preferred over MX 20, which acts as a backup mail route.

What are DNSKEY, DS, and RRSIG records for?

These are DNSSEC records. DNSKEY holds a zone's public key, RRSIG is a signature over a record set, and DS in the parent zone references the child's key. Together they let resolvers verify that DNS answers are authentic.

Is there a dedicated SPF record type?

There was a type 99 SPF record, but it is deprecated. SPF policies are now published as ordinary TXT records, which is what every mail provider expects today.

DNS Record Type Reference

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Know every DNS record type

The Domain Name System uses many resource record types, each carrying a different kind of data: addresses, mail routing, aliases, text policies, service locations, and DNSSEC signatures. Knowing which record to create — and the exact format of its data — saves a lot of trial and error when configuring a domain. This reference explains each common type, the RFC that defines it, and an example you can model your own records on.

How it works

Each record type is identified by a short name (like A or MX) and defined in an RFC. The most fundamental are A and AAAA, which map a hostname to an IPv4 or IPv6 address. CNAME aliases one name to another. MX routes email with a priority value where the lowest number wins. TXT carries arbitrary text and is the vehicle for SPF, DKIM, and DMARC email policies. NS and SOA define a zone’s authority. The DNSSEC family — DNSKEY, DS, and RRSIG — adds cryptographic verification. Each example line shows the canonical zone-file format: name, type, then the record data.

Tips and notes

You cannot place a CNAME at the apex of a zone (the bare domain), which is why providers offer ALIAS or ANAME pseudo-records or the newer HTTPS and SVCB records. Email deliverability depends on getting MX, SPF, DKIM, and DMARC right together. Use CAA records to restrict which certificate authorities can issue certificates for your domain. All searching runs locally in your browser — no queries are sent anywhere.