Security certificate is nothing but information (often stored as a text file) that is used by the SSL protocol to establish a secure connection. It contains information about who it 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. In order for an SSL connection to be created both sides must have a valid Security Certificate.

Security certificates are very important for organizations that process credit card orders while doing online business. Usually, the company that hosts the website one for free; otherwise, it may cost up to $10 per month on top of the normal hosting charges. If you want to use your own domain name as a secure server rather than your hosting companies domain name and certificate, you'll need to purchase your own certificate which will cost between $125 and $350 a year.

Functions of secure server:
::	Encrypts information.
::	Identifies itself to the browser by presenting a digital certificate to the browsers who request a secure connection..