Wildcard SSL certificates eliminate the need to install a separate digital certificate for each subdomain by allowing you to use an unlimited number of subdomains in the certificate. Any site that has a domain that matches *.yourdomain.com (where * can be anything and yourdomain.com is any domain with the wildcard certificate installed on) will be secured by a Wildcard SSL digital certificate. And since Wildcard SSL is a high assurance ssl certificate, it provides a high level of validation to your customers. Wildcards can even be used within multi-domain or Exchange Server certificates (see UCC certificates or EV UCC certificates for more details. Standard wildcard rates apply per wildcard domain as a Subject Alternative Name or SAN)
