It can be anything! An apex, subdomain, or even a URL.

Results forns1.reg.ru

Resolver

Location

A

Name	TTL	Value
ns1.reg.ru	86400	176.99.13.11Reg.RU / "Domain names registrar REG.RU", Ltd
ns1.reg.ru	86400	176.99.13.13Reg.RU / "Domain names registrar REG.RU", Ltd
ns1.reg.ru	86400	176.99.13.15Reg.RU / "Domain names registrar REG.RU", Ltd
ns1.reg.ru	86400	176.99.13.17Reg.RU / "Domain names registrar REG.RU", Ltd
ns1.reg.ru	86400	194.58.117.11 / Reg.Ru
ns1.reg.ru	86400	194.58.117.13 / Reg.Ru
ns1.reg.ru	86400	194.58.117.15 / Reg.Ru
ns1.reg.ru	86400	194.58.117.17 / Reg.Ru

Name	TTL	Value
ns1.reg.ru	86400	2a00:f940:9::1:1
ns1.reg.ru	86400	2a00:f940:9::2:1