SSL stands for Secure Sockets Layer. It is the most widely deployed security protocol used today. It is essentially a protocol that provides a secure channel between two machines operating over the Internet or an internal network. In today’s Internet focused world, we typically see SSL in use when a web browser needs to securely connect to a web server over the insecure Internet.
SSL is a transparent protocol, which requires little interaction from the end user when establishing a secure session. For example, in the case of a browser, users are alerted to the presence of SSL when the browser displays a padlock, or in the case of Extended Validation SSL the address bar displays both a padlock and a green bar. This is the key to the success of SSL – it is incredibly simple to use.