Difference Between Wildcard SSL Vs SAN Certificate

There are two types of Multi use SSL certificates available today:

Wildcard Certificates

They are widely used to secure multiple subdomains under a single unique fully qualified domain name. The benefit with this certificate is that that it not only makes it simple to manage the certificate, but it also helps you in lowering your administrative costs. It provides immediate protection to your current and future subdomains.

SAN Certificates

They are used to protect multiple domain names with a single certificate. They are different than wildcard certificates in a way that SAN certificates only support fully qualified domain names which are entered in the certificate.
Most SAN certificates can support more than 100 different fully qualified domain names in a single certificate (depending upon the issuing certificate authority).

SAN certificates are most useful to businesses or organizations that are looking to use different domain names to perform internet facing services. For example, if an organization uses two domains, www.exmpl.net and www.exmpl.com then only a SAN certificate will provide security to the unified communication of both these fully qualified domain names.

They would need two wildcard certificates for .net and .com as they are two different domains.

Note: SAN certificates are not compatible with wildcard certificates