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

Results forgamma.ap-southeast-3.ses.aws.a2z.com

Resolver

Location

NS

Name	TTL	Value
gamma.ap-southeast-3.ses.aws.a2z.com	172800	ns-203.awsdns-25.com
gamma.ap-southeast-3.ses.aws.a2z.com	172800	ns-964.awsdns-56.net
gamma.ap-southeast-3.ses.aws.a2z.com	172800	ns-1451.awsdns-53.org
gamma.ap-southeast-3.ses.aws.a2z.com	172800	ns-1555.awsdns-02.co.uk

Name	TTL	Value
gamma.ap-southeast-3.ses.aws.a2z.com	900	ns-203.awsdns-25.com awsdns-hostmaster.amazon.com 1 7200 900 1209600 86400