SSL - Secure Sockets Layer
If you want to send any sensitive information (like a credit card number, user id and password or any other personal information) over the Internet, you need to secure that information with the SSL or Secure Socket Layer protocol. If an e-commerce or a banking website is not SSL-enabled, your customer data might not be secure during a transit.
A Secure Sockets Layer is a cryptographic protocol used to encrypt user data in an online transaction. Encrypting user data with SSL removes the problem of forgery, eavesdropping and data tampering.
SSL creates a secure channel between the web server and your web browser. An SSL enabled website could be accessed with a prefix "https://" instead of "http://". The SSL enabled websites generates trust among their users that the information they are entering is secure and not being tampered.
To enable SSL on a website, you need to get an SSL certificate from the Certificate Authority (CA). A Certificate authority is an entity that offers an SSL certificate to organizations or individuals, after validating them. A typical SSL certificate binds together: a domain name, server and hosting details, and the identification of an organization & its location.