How does NS server work?

Question

Domain Name System

Explain to a stupid and naive person)) how? I will show on the example of hostinger.com and the picture

(the arrows show where the whois record of the domain goes)
for example any1.hostinger.com leads to any1.hostinger.com and to any2.hostinger.com
which in turn - any2.hostinger.com leads to any1 .hostinger.com and any2.hostinger.com

Answer 1

whois7.ru/?s=dig&q=any1.hostinger.com&ns=8.8.8.8&t...

; <<>> DiG 9.8.7 <<>> any1.hostinger.com IN A +nostats +noquestion +trace
;; global options: +cmd
.			80116	IN	NS	f.root-servers.net.
.			80116	IN	NS	a.root-servers.net.
.			80116	IN	NS	b.root-servers.net.
.			80116	IN	NS	h.root-servers.net.
.			80116	IN	NS	e.root-servers.net.
.			80116	IN	NS	k.root-servers.net.
.			80116	IN	NS	l.root-servers.net.
.			80116	IN	NS	g.root-servers.net.
.			80116	IN	NS	m.root-servers.net.
.			80116	IN	NS	i.root-servers.net.
.			80116	IN	NS	c.root-servers.net.
.			80116	IN	NS	d.root-servers.net.
.			80116	IN	NS	j.root-servers.net.
;; Received 228 bytes from 77.88.8.8#53(77.88.8.8) in 10528 ms

com.			172800	IN	NS	a.gtld-servers.net.
com.			172800	IN	NS	b.gtld-servers.net.
com.			172800	IN	NS	c.gtld-servers.net.
com.			172800	IN	NS	d.gtld-servers.net.
com.			172800	IN	NS	e.gtld-servers.net.
com.			172800	IN	NS	f.gtld-servers.net.
com.			172800	IN	NS	g.gtld-servers.net.
com.			172800	IN	NS	h.gtld-servers.net.
com.			172800	IN	NS	i.gtld-servers.net.
com.			172800	IN	NS	j.gtld-servers.net.
com.			172800	IN	NS	k.gtld-servers.net.
com.			172800	IN	NS	l.gtld-servers.net.
com.			172800	IN	NS	m.gtld-servers.net.
;; Received 496 bytes from 192.58.128.30#53(j.root-servers.net) in 217 ms

hostinger.com.		172800	IN	NS	any1.hostinger.com.
hostinger.com.		172800	IN	NS	any2.hostinger.com.
;; Received 101 bytes from 192.54.112.30#53(h.gtld-servers.net) in 177 ms

any1.hostinger.com.	14400	IN	A	153.92.2.8
;; Received 52 bytes from 153.92.2.8#53(any1.hostinger.com) in 48 ms

Answer 2

We'll tell rumors)))
It is required to maintain 2 name servers....
Roofing felts according to the RFC standard Roofing
felts according to the "providers" standard for connecting to root servers
.... moreover, on different subnets.
For operational reliability.
Or it was necessary to tell how DNS works in general? )))

Answer 3

And what is the real question?
NS -> name servers -> just servers with a raised DNS service/service/daemon (ms dns/bind/dnsmasq etc.)
There is DNS - a hierarchically distributed domain name system.
Someone should be responsible for any area. Two name server dns are responsible for the hostinger.com domain zone.
One holds the master replica of all hosts (and other DNS records), the other is secondary. Two of them are needed exclusively for High Availability. (You can do three or four, and probably no one will stop you from making fifteen of them)
I.e. if these two servers are turned off - after some time, when cached entries disappear from the cache -> no one on the Internet can resolve names from this domain anymore ...