DNS

The Domain Name System (DNS) is the internet's phone book. When you type a domain like radartrek.com, DNS looks up the IP address of the server hosting that site so your browser knows where to send its request. Without DNS, you'd have to remember numeric IP addresses for every site.

• —Every domain purchase and every deployment involves pointing DNS records at the right server.
• —DNS changes can take time to propagate — this is why a new domain sometimes "isn't working yet."
• —Misconfigured DNS is one of the most common reasons a site or email setup breaks.

This is the exact lesson that covers this term in depth — with examples, diagrams, and a hands-on exercise.