4.
...then the local NS asks the root nameservers: “What
NS knows about the ‘Amazon.com’ domain?”
5.
The root NS answers with something like “Here,
ask this NS: 1.2.3.4” (it knows this from Amazon’s
original domain registration; that’s what you
do when you buy a dot-com.)
6.
Your local NS then asks 1.2.3.4 “what’s
the IP for ‘www’?”
4.
...then the local NS asks the root nameservers: “What
NS knows about the ‘Amazon.com’ domain?”