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

Results for*.kikshark.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-03-14T12:05:16.484	2019-03-14T11:05:15	2019-06-12T11:05:15	mybethlehemlearningcenter.com	*.kikshark.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-14T12:05:16.484	2019-03-14T11:05:15	2019-06-12T11:05:15	mybethlehemlearningcenter.com	*.kikshark.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-14T12:05:15.665	2019-03-14T11:05:15	2019-06-12T11:05:15	mybethlehemlearningcenter.com	*.kikshark.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-14T12:05:15.665	2019-03-14T11:05:15	2019-06-12T11:05:15	mybethlehemlearningcenter.com	*.kikshark.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3