SSL is short for Secure Sockets Layer.
It is a mechanism for encrypting data between your computer and another, as well as verifying the identity of a server. One can specify a special URL to tell a web browser that it needs to open a secure connection and encrypt all data.
URL not using SSL: http://www.example.com
URL using SSL: https://www.example.com
You may have seen SSL used when you login to your bank’s online web access to view your account information or when using an eCommerce shopping cart checkout.