I don't think this article is technically deep enough to be of any significant value ( at least for me ).

Not discussed at all ( and that people interested in the topic should know ) :

1. NS, SOA records

2. What exactly is TXT record.

3. What's the difference between CNAME, A Records

Later on I also checked the first article [1], which even doesn't explain what TLD is.

[1] https://pressable.com/blog/2014/12/04/dns-management-basics/