DNS

Summary

The Domain Name System translates human-readable domain names (like google.com) into IP addresses that computers use to locate servers. A DNS lookup can involve caches, recursive resolvers, root servers, TLD servers, and authoritative name servers before the browser receives the address it needs.

• 1Run `nslookup` or `dig` on a domain to see DNS resolution in action. Validate your understanding by applying it in a small practical example.
• 2Learn the difference between A, CNAME and MX records. Focus on understanding the underlying reason it works, not only memorizing the definition.
• 3Understand how DNS caching affects how fast a site loads for repeat visitors.