What Is DNS?

DNS is the system that turns names such as example.com into technical records that computers can use. Most people notice DNS only when it breaks.

Key points

• Root servers point to TLD servers.
• TLD servers point to authoritative name servers.
• Authoritative servers publish the domain zone records.
• Recursive resolvers cache answers and reply to users.

Where dig fits

Dig is useful because it lets you ask DNS one precise question at a time. Instead of guessing why a website, email system, or service is failing, you can check the record type that controls that part of the setup.

Practical next step

Start with the record type that matches the symptom. Use A or AAAA for website address issues, MX and TXT for email, CNAME for provider aliases, and NS or SOA for delegation problems.