You can issue both SSH Certificates and X.509 certificates using Certificate Manager. You'll need to activate SSH for Certificate Manager before you can issue SSH certs.
X.509 certificates are designed to be ubiquitous. They can be used in SSL/TLS, S/MIME, EAP-TLS, and even in the SSH protocol for web applications, databases, VPNs, WiFi, digital signatures for document signing, and all kinds of other places. (read more)
If you'd like to use your Certificate Manager account to issue SSH Certificates as well, contact us to activate SSH on Certificate Manager.
Learn more about SSH versus X.509 Certificates here.