DNS turns names into routing information. For web apps, the most common records are A, AAAA, and CNAME.
dig example.com Adig www.example.com CNAME
CNAME aliases one hostname to another. The apex domain often cannot be a raw CNAME, depending on provider behavior.
WARNING
DNS changes are not always instant. Resolver caches may keep old values until TTL expires.
Further Learning
“DNS record types A CNAME TXT MX” — record guide
“dig command examples” — DNS debugging
“DNS TTL propagation” — cache behavior
DNS Records
DNS is the internet’s contacts app. You type a name (example.com), and DNS looks up the actual address to connect to. Behind a domain is a little list of records that tell the internet where different things live.
The records you’ll actually use
A record — points a name to an IP address (example.com → 142.250.80.46).
CNAME — points a name to another name (an alias, e.g. www.example.com → example.com).
MX — where email for the domain goes.
TXT — free-text notes, often used to prove you own the domain.
For hosting a website, you’ll mostly set an A record (or a CNAME to your host, like Vercel).
Changes aren’t instant
When you change a DNS record, the whole internet doesn’t update immediately. Computers cache the old answer for a while — that waiting period is set by the TTL (time-to-live).
WARNING
After changing DNS, you might still see the old value for minutes or hours until the cache (TTL) expires. This is normal — it’s not broken, just propagating.
One common gotcha
NOTE
Your root/apex domain (example.com with no www) often can’t use a plain CNAME — many providers offer a special “ALIAS” or “flattened CNAME” for this. If a CNAME on the bare domain won’t save, that’s why.
In one sentence
DNS translates a domain name into an address using records — mainly A (name → IP) and CNAME (name → another name) — and changes take time to spread because of caching (TTL).
Want to go deeper?
Switch to Expert mode above for dig debugging commands and the full record-type details.