Every time you visit a website, send an email, or connect to a server, the Domain Name System (DNS) quietly does the work of translating a human-friendly name like example.com into the numbers and routing information computers actually use. The instructions that make this happen are called DNS records. Understanding them is essential for launching a site, setting up email, or moving to a new host. This guide explains the most important record types in plain English, with real examples.
What Is a DNS Record?
A DNS record is a single line of instruction stored in your domain’s zone file on a DNS server. Each record has a type (what kind of information it holds), a name (which hostname it applies to), a value (the answer), and a TTL (how long resolvers may cache it). Together, these records tell the internet where to find your website, your mail server, and anything else attached to your domain.
The Essential Record Types
| Record | Purpose | Example value |
|---|---|---|
| A | Points a hostname to an IPv4 address | 203.0.113.10 |
| AAAA | Points a hostname to an IPv6 address | 2001:db8::1 |
| CNAME | Aliases one hostname to another | example.com |
| MX | Specifies the mail server for the domain | 10 mail.example.com |
| TXT | Holds text data (SPF, DKIM, verification) | "v=spf1 mx -all" |
| NS | Delegates the domain to its nameservers | ns1.host.com |
| SRV | Defines the host and port for a service | 10 5 443 sip.example.com |
A and AAAA Records
The A record is the most fundamental record — it maps a name to an IPv4 address. The AAAA record does the same for IPv6. A typical site has both for the root domain and the www subdomain.
example.com. 3600 IN A 203.0.113.10
www.example.com. 3600 IN A 203.0.113.10
example.com. 3600 IN AAAA 2001:db8::1CNAME Records
A CNAME points one name at another name rather than an IP. It’s ideal for subdomains that should always follow the root. Note: you cannot place a CNAME on the root domain (the “naked” example.com) alongside other records.
blog.example.com. 3600 IN CNAME example.com.
shop.example.com. 3600 IN CNAME mystore.myshopify.com.MX Records
MX (Mail eXchange) records tell other servers where to deliver email for your domain. The number is the priority — lower values are tried first, so you can add a backup mail server with a higher number.
example.com. 3600 IN MX 10 mail.example.com.
example.com. 3600 IN MX 20 backup-mail.example.com.TXT Records
TXT records store free-form text and power email authentication (SPF, DKIM, DMARC) and domain-ownership verification for services like Google and Microsoft.
example.com. 3600 IN TXT "v=spf1 include:_spf.google.com -all"
example.com. 3600 IN TXT "google-site-verification=abc123..."Understanding TTL and Propagation
The TTL (Time To Live), in seconds, tells resolvers how long to cache a record before checking again. A low TTL (e.g. 300) means changes take effect quickly but adds more lookups; a high TTL (e.g. 86400) is efficient but slow to update. Before a planned migration, lower the TTL a day in advance so the switch propagates fast.
How to Check DNS Records
# Look up specific record types
dig example.com A +short
dig example.com MX +short
dig example.com TXT +short
# Query a specific resolver (e.g. Google's)
dig @8.8.8.8 example.com AOn Windows you can use nslookup example.com for a quick check.
Conclusion
DNS records are the address book of the internet: A/AAAA point names to servers, CNAME creates aliases, MX routes email, TXT proves identity, and NS delegates the whole domain. Once you can read a zone file and use dig to verify changes, managing your domain — and troubleshooting it — becomes straightforward.
