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

Results forexample.aboutbits.it

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-02-14T01:40:04.78	2019-02-14T00:40:03	2019-05-15T00:40:03	example.aboutbits.it	example.aboutbits.it	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-02-14T01:40:04.011	2019-02-14T00:40:03	2019-05-15T00:40:03	example.aboutbits.it	example.aboutbits.it	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-14T10:20:29.305	2018-12-14T09:20:28	2019-03-14T09:20:28	example.aboutbits.it	example.aboutbits.it	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-14T10:20:28.287	2018-12-14T09:20:28	2019-03-14T09:20:28	example.aboutbits.it	example.aboutbits.it	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-13T15:18:07.729	2018-12-13T14:18:06	2019-03-13T14:18:06	example.aboutbits.it	example.aboutbits.it	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2018-12-13T15:18:07.001	2018-12-13T14:18:06	2019-03-13T14:18:06	example.aboutbits.it	example.aboutbits.it	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3