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

Results forcrt.rootca4.amazontrust.com

Resolver

Location

A

Name	TTL	Value
crt.rootca4.amazontrust.com	60	3.167.56.41AWS CloudFront (GLOBAL) / Amazon.com, Inc.
crt.rootca4.amazontrust.com	60	3.167.56.43AWS CloudFront (GLOBAL) / Amazon.com, Inc.
crt.rootca4.amazontrust.com	60	3.167.56.82AWS CloudFront (GLOBAL) / Amazon.com, Inc.
crt.rootca4.amazontrust.com	60	3.167.56.112AWS CloudFront (GLOBAL) / Amazon.com, Inc.