DNS Records Explained: A Plain-English Guide to A, CNAME, MX, and TXT

DNS has a reputation for being scary precisely because it's invisible when it works. In reality, most domains only ever need a handful of record types, and each one does one specific, easy-to-understand job.

What DNS records actually do

Think of DNS as the internet's phonebook: it translates a human-readable name like yourdomain.com into the machine data that actually routes traffic — an IP address, a mail server, or a piece of arbitrary text used for verification. Every record has the same basic shape: a type, a name (the subdomain or @ for the root), a value, and a TTL (how long it's cached before it's rechecked).

A and AAAA records — pointing your domain at a server

An A record points a name at an IPv4 address; an AAAA record does the same for IPv6. This is the most common record you'll touch — it's how you tell the internet which physical (or virtual) server actually hosts your site. Use @ as the name for your root domain (yourdomain.com) or a specific subdomain like app for app.yourdomain.com.

CNAME records — pointing a subdomain at another domain name

A CNAME aliases one name to another hostname instead of an IP address — useful for pointing www.yourdomain.com at yourdomain.com, or a subdomain at a third-party service like a CDN or a docs platform. One important technical restriction: a CNAME can't coexist with any other record on the same name, and it can never be placed on the root/apex domain itself — for the apex you'll use an A/AAAA record, or your provider's ALIAS-style record if you need to point the apex at a hostname.

MX records — where your domain's email goes

Mail exchange (MX) records tell the internet which mail server handles email sent to your domain. Each MX record has a priority number — lower numbers are tried first — which lets you list a primary and backup mail server. If you're using a hosted email provider (like Google Workspace or Microsoft 365), they'll give you the exact MX values to add.

TXT records — verification and anti-spoofing

TXT records hold arbitrary text and cover two very different jobs in practice: proving you own a domain to a third-party service (search consoles, hosting providers, marketing tools all use this), and authenticating your outgoing email so it doesn't get flagged as spam or spoofed.

• SPF — lists which mail servers are allowed to send email on behalf of your domain.
• DKIM — attaches a cryptographic signature to outgoing mail so receivers can verify it wasn't altered in transit.
• DMARC — tells receiving mail servers what to do with messages that fail SPF or DKIM checks, and where to send reports about them.

TTL: how fast changes take effect

TTL (time to live) is how many seconds a resolver caches a record before checking again — a common default is 3600 seconds (one hour). If you're planning a migration, lower the TTL on the relevant records a day or two ahead of time so the eventual change propagates faster, then raise it back afterward once things are stable.

A simple example: setting up a new subdomain

• Want blog.yourdomain.com hosted on a separate blogging platform? Add a CNAME record with the name blog pointing at the hostname your platform gives you.
• Want app.yourdomain.com to hit your own server directly? Add an A record with the name app pointing at that server's IP address instead.

“You don't need to understand all of DNS — you need to understand the five record types you'll actually touch, and when.”

Once you've set records for hosting, email, and verification a couple of times, the rest of DNS stops feeling like a black box — it's just a short, repeatable checklist.