Wildcard certificates
are great for protecting multiple sub-domains on a single domain. In many cases, the wildcard cert makes more sense than a SAN because it allows for unlimited sub-domains and you don’t need to define them at the time of purchase. You could provision *.domaineexmaple.com and in at anytime during the life of the certificate, you decided to add www3.domaineexmaple.com or shop.domaineexmaple.com, that cert would just work, no reissue required.
On the other hand, if you need to protect multiple domain names, then the SAN certificate might be the right choice. Protecting alternative domains with the same website (domaineexmaple.com and domaineexmaple.net) is a great example. One caveat – you need to define the additional domains and add them to the certificate for it to work.
SAN certificates
, like wildcard certificates, are a great way to save some money and also to make administration a bit easier as you can reduce the number of certificates provisioned since they cover multiple domains since its allow you to protect multi domains with one certificate and this also save money .