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

Results forfreer.crscript.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-02-08T19:25:09.955	2019-02-08T18:25:08	2019-05-09T18:25:08	freer.crscript.com	freer.crscript.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-08T19:25:08.97	2019-02-08T18:25:08	2019-05-09T18:25:08	freer.crscript.com	freer.crscript.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-10T10:32:52.969	2018-12-10T09:32:52	2019-03-10T09:32:52	freer.crscript.com	freer.crscript.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-10T10:32:52.028	2018-12-10T09:32:52	2019-03-10T09:32:52	freer.crscript.com	freer.crscript.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-10-11T05:00:28.138	2018-10-11T04:00:27	2019-01-09T04:00:27	freer.crscript.com	freer.crscript.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-10-11T05:00:27.425	2018-10-11T04:00:27	2019-01-09T04:00:27	freer.crscript.com	freer.crscript.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3