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

Results forwww.arbitech.org

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-07-19T10:47:24.049	2021-07-19T09:47:23	2021-10-17T09:47:21	www.arbitech.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=R3
2021-07-19T10:47:23.874	2021-07-19T09:47:23	2021-10-17T09:47:21	www.arbitech.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=R3
2021-07-02T19:05:48.206	2021-07-02T18:05:47	2021-09-30T18:05:46	arbitech.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=R3
2021-07-02T19:05:47.51	2021-07-02T18:05:47	2021-09-30T18:05:46	arbitech.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=R3
2020-07-31T23:54:57.789	2020-07-31T22:54:57	2020-10-29T22:54:57	www.arbitech.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-07-31T23:54:57.504	2020-07-31T22:54:57	2020-10-29T22:54:57	www.arbitech.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-07-11T22:45:59.441	2020-07-11T21:45:59	2020-10-09T21:45:59	smach.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-07-11T22:45:59.265	2020-07-11T21:45:59	2020-10-09T21:45:59	smach.org	www.arbitech.org	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3