How a DNS lookup actually works
When you type a domain into your browser, this sequence happens in roughly 50–200 ms:
- Your browser checks its own cache. Hit? Done.
- Your operating system checks its resolver cache.
- Your configured resolver (often your ISP, or 1.1.1.1 / 8.8.8.8) checks its cache.
- If still missing, it queries the root nameservers, then the TLD (.com) servers, then the domain's authoritative nameservers.
- The IP address is returned and cached at every level for the record's TTL.
The record types you'll actually encounter
- A — maps a domain to an IPv4 address. The most common record.
- AAAA — same as A but for IPv6.
- CNAME — an alias pointing one domain to another. Often used for subdomains pointing at SaaS providers.
- MX — mail exchange records. Tells the world which server accepts email for the domain.
- TXT — arbitrary text. Used for SPF, DKIM, DMARC, and domain verification by Google, Stripe, etc.
- NS — declares the authoritative nameservers for the domain.
Reading DNS results without confusion
Each result has three things you care about: the value (the IP or target), the TTL (cache duration in seconds), and the type. If you query an A record and see an empty answer, the domain doesn't have one — it might only have AAAA or CNAME. Always query the specific type you need rather than relying on a single check.