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

Results for*.apptesting.co

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-09-05T11:55:02.925	2020-09-02T00:00:00	2021-09-02T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-09-05T11:55:02.925	2020-09-02T00:00:00	2021-09-02T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-09-02T13:29:38.786	2020-09-02T00:00:00	2021-09-02T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2020-09-02T13:29:38.786	2020-09-02T00:00:00	2021-09-02T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, O="Cloudflare, Inc.", CN=Cloudflare Inc ECC CA-3
2019-10-09T10:45:14.212	2019-10-04T00:00:00	2020-10-03T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, ST=CA, L=San Francisco, O="CloudFlare, Inc.", CN=CloudFlare Inc ECC CA-2
2019-10-09T10:45:14.212	2019-10-04T00:00:00	2020-10-03T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, ST=CA, L=San Francisco, O="CloudFlare, Inc.", CN=CloudFlare Inc ECC CA-2
2019-10-04T21:05:17.486	2019-10-04T00:00:00	2020-10-03T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, ST=CA, L=San Francisco, O="CloudFlare, Inc.", CN=CloudFlare Inc ECC CA-2
2019-10-04T21:05:17.486	2019-10-04T00:00:00	2020-10-03T12:00:00	sni.cloudflaressl.com	*.apptesting.co	C=US, ST=CA, L=San Francisco, O="CloudFlare, Inc.", CN=CloudFlare Inc ECC CA-2