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

Results fornet.suits.cool

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2023-02-26T11:23:25.902	2023-02-26T10:23:25	2023-05-27T10:23:24	arbitragedata.net.suits.cool	arbitragedata.net.suits.cool	C=US, O=Let's Encrypt, CN=R3
2023-02-26T11:23:25.633	2023-02-26T10:23:25	2023-05-27T10:23:24	arbitragedata.net.suits.cool	arbitragedata.net.suits.cool	C=US, O=Let's Encrypt, CN=R3
2023-01-23T08:55:24.046	2023-01-23T07:55:23	2023-04-23T07:55:22	fundamentum.vc	nintendoforum.net.suits.cool	C=US, O=Let's Encrypt, CN=R3
2023-01-23T08:55:23.736	2023-01-23T07:55:23	2023-04-23T07:55:22	fundamentum.vc	nintendoforum.net.suits.cool	C=US, O=Let's Encrypt, CN=R3