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

Results forwww.teridion-test.atlassian.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2018-10-16T07:22:37.023	2018-10-16T06:22:36	2019-01-14T06:22:36	teridion-test.atlassian.net	teridion-test.atlassian.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-10-16T07:22:36.813	2018-10-16T06:22:36	2019-01-14T06:22:36	teridion-test.atlassian.net	teridion-test.atlassian.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-10-11T06:40:08.379	2018-10-11T05:40:08	2019-01-09T05:40:08	teridion-test.atlassian.net	teridion-test.atlassian.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-10-11T06:40:08.201	2018-10-11T05:40:08	2019-01-09T05:40:08	teridion-test.atlassian.net	teridion-test.atlassian.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3