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

Results forwww.cloud.leith.de

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-04-06T23:13:34.565	2021-04-06T22:13:34	2021-07-05T22:13:34	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=R3
2021-04-06T23:13:34.353	2021-04-06T22:13:34	2021-07-05T22:13:34	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=R3
2021-02-05T19:31:58.988	2021-02-05T18:31:58	2021-05-06T18:31:58	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=R3
2021-02-05T19:31:58.885	2021-02-05T18:31:58	2021-05-06T18:31:58	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=R3
2020-12-07T20:23:17.418	2020-12-07T19:23:17	2021-03-07T19:23:17	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=R3
2020-12-07T20:23:17.098	2020-12-07T19:23:17	2021-03-07T19:23:17	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=R3
2020-10-08T15:21:42.404	2020-10-08T14:21:42	2021-01-06T14:21:42	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-10-08T15:21:42.179	2020-10-08T14:21:42	2021-01-06T14:21:42	leith.cloud	www.cloud.leith.de	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3