A wildcard certificate secures domain names along with all subdomains of the domain. For example, a Wildcard certificate issued to *.mydomain.com can be used to secure the following host names:

• mydomain.com
• www.mydomain.com
  
• login.mydomain.com
• secure.mydomain.com
• support.mydomain.com etc.

Namecheap offers PositiveSSL Wildcard, EssentialSSL Wildcard and PremiumSSL Wildcard certificates.