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

Results forww25.webdisk.khalidlab.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-05-20T14:43:18.142	2021-05-20T13:43:17	2021-08-18T13:43:17	ww25.webdisk.khalidlab.com	ww25.webdisk.khalidlab.com	C=US, O=Let's Encrypt, CN=R3
2021-05-20T14:43:17.88	2021-05-20T13:43:17	2021-08-18T13:43:17	ww25.webdisk.khalidlab.com	ww25.webdisk.khalidlab.com	C=US, O=Let's Encrypt, CN=R3
2021-02-25T07:08:34.844	2021-02-25T06:08:34	2021-05-26T06:08:34	ww25.webdisk.khalidlab.com	ww25.webdisk.khalidlab.com	C=US, O=Let's Encrypt, CN=R3
2021-02-25T07:08:34.393	2021-02-25T06:08:34	2021-05-26T06:08:34	ww25.webdisk.khalidlab.com	ww25.webdisk.khalidlab.com	C=US, O=Let's Encrypt, CN=R3