Where is the A-record created?

Question

Domain Name System

The domain is directed to hosting using ns. Its subdomain needs to be directed to another IP via an A-record. Tell me, where is the A-record for the subdomain created, in the domain control panel or on the hosting, where do ns point?

Answer 1

Good afternoon!
A domain has only one working DNS zone, the one pointed to by ns-records. In your case, this is hosting. If the required entry is added at the registrar, it will not work

Answer 2

Anywhere
Physically, it does not matter.
If you have a DNS server on the server and the A record of the main domain goes there, then it can create subdomains itself,
in your case it will be easier to create subdomains in the same place as the A record of the main domain
for example

site.ru  A  1.1.1.1
www    A  1.1.1.1
sub1      A  2.2.2.2

But here it already depends on the web muzzle that you have for editing DNS
. For example, for some it will be different

site.ru  A  1.1.1.1
www.site.ru    A  1.1.1.1
sub1.sute.ru      A  2.2.2.2

or with @ which by the way is outside the RFC standard but is used

@  A  1.1.1.1
[email protected]    A  1.1.1.1
[email protected]      A  2.2.2.2

Do not forget that the DNS server only compares the domain with the A record and, in principle, your subdomain could get an A record in the RU zone if you had such garters there and someone in their dns server could add this A record , in fact dns works like this
www.site.ru.
read from the end
. the zero level of the domain is at the end of any domain (these are the owners of the domain zone, yes it has a physical owner) and there is a dns server that knows only root domains, it knows the RU COM zones, etc. and gives them an A record, but it is the same dns the server, like everyone else, could have already given your a record, but instead it sends this question to another dns server using NS records, let it sort itself out.
accordingly, RU already refers to your domain and its NS server, it can also either immediately give records or refer to another dns server. and so on, distributed load.
Accordingly, you can assign all domains below the domain you purchased at any time, or delegate them to a separate dns server.