This is so nicely explained, Jaynil! This is one of the simplest explaination on this topic I ever read. So much clarity. Thanks for this.
I have a few questions here:
1. What is recursive resolver doing here? I see this acting just as a hopper between User and Authoritative Server. Is my assumption correct? Would we still be fine connecting to Authoritative Server directly?
2. Is Fastly your authoritative server where you configure the IP addresses and return the closest one to the user based on their subnet?
3. What is @ns1.google.com here?
4. "EDNS is the unsung hero of how internet works today and this post attempts to change that." You mentioned this in conclusion. What part are you referring to change?
PS: This is a great article. ;)