Term · Security & infrastructure
DNS (domain name system)
DNS — the domain name system — is the internet's directory. It translates human-readable names like example.az into the technical addresses of servers, and it tells the world where your website is hosted, which servers receive your email and which services may act on your domain's behalf.
[ 01 ]
Explained
Common record types
| Record | Purpose |
|---|---|
| A / AAAA | Points a name to an IPv4 / IPv6 address |
| CNAME | Points a name to another name |
| MX | Specifies mail servers for the domain |
| TXT | Text data: verification, SPF, DMARC and more |
| NS | Nameservers responsible for the domain |
| CAA | Which certificate authorities may issue certificates |
TTL and propagation
Each record has a TTL (time to live) — how long resolvers may cache it. After a change, some users see the old value until caches expire. Lowering TTL before planned changes speeds up the switch.
Why DNS changes break email
When a website moves, only the website records should change. If DNS hosting is moved without copying MX and TXT records, email stops arriving and email authentication fails. See domain, DNS and email setup.
Security
- Protect registrar and DNS accounts with strong passwords and two-factor authentication.
- Use SPF, DKIM and DMARC to protect email.
- Consider DNSSEC where supported, which protects against forged DNS responses.
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FAQ
Frequently asked questions
Where is our DNS managed?
At the provider set as your domain's nameservers — often the registrar, hosting provider or a CDN.
How long do DNS changes take?
From minutes to a day or two, depending on TTL and caching.