A Wildcard SSL Certificate helps enable SSL encryption on multiple sub-domains using a single certificate as long as the domains are controlled by the same organization and share the same second-level domain name. A sub domain is a separate website listed under a domain. Examples are clothes.shoppingmall.com or shoes.shoppingmall.com. Search engines register these as separate sites, even though the host name is the same. When there is a lot if information to be presented on one website or when the business representing the website has logically different categories/divisions ? sub domains are the best way to organize the information on the website. Sub domains can work well if your site branches into different areas, for example topic.example.com or topic2.example.com in effect these sub domains are unique sites in their own right, but to the user, they appear to be an extension of one main site.

Wildcard Certificate is a unique product that gives the ability to secure multiple sub-domains within the company through a single certificate. A wild-carded certificate can be used to secure the certificate owner's website sub-domains (e.g. shop.yourcompany.com, pay.yourcompany.com etc) with a single certificate. If there is a requirement of securing multiple sub-domains on a website, then a "Wild-carded" certificate is the ideal choice. A Wildcard SSL Certificate helps in achieving SSL encryption on multiple sub-domains with the help of a single certificate as long as the sub domains are on one same physical server, share the same second-level domain name and are under the control of a single organization. For example a Wildcard issued to a company XYZ using the domain www.xyz.com can be used to secure the following domains: login.xyz.com, support.xyz.com, and careers.xyz.com