Certification, issued by a third party, proving the site supports encryption to protect information being sent from the shopper's computer to the host's server. Visible evidence is a small padlock icon in the browser's status bar. A secure certificate increases customer confidence in the site.
A chunk of information on a SERVER that is used to establish a secure connection between that server and another server. Secure Certificates contain information about who the certificate belongs to, who it was issued by, a unique serial number or other unique identification, valid dates, and an ENCRYPTED "fingerprint" that can be used to verify the contents of the certificate.