What is DNS?
Learn what DNS is, how domain name resolution works, and how records like A, MX, and TXT fit into the system.
What DNS is
DNS (Domain Name System) is the system that translates human-readable domain names into IP addresses that computers use to communicate.
When you type a domain into a browser, DNS is responsible for finding the correct server behind that name.
You can inspect DNS records using DNS Pro: https://app.dnspro.co.uk/dns-lookup
How DNS resolution works
- A client requests a domain lookup
- A resolver queries DNS servers
- Authoritative servers return the answer
- The resolver returns the IP to the client
Common DNS record types
- A → maps a hostname to an IPv4 address
- AAAA → maps a hostname to an IPv6 address
- MX → defines mail servers for a domain
- TXT → stores arbitrary text (often used for verification and email security)
- CNAME → aliases one hostname to another
Why DNS matters
DNS is critical infrastructure for the internet. If DNS fails or is misconfigured, services like websites and email will not function correctly.
Basic validation commands
dig example.com
nslookup example.com