"What is SSL?"

SSL is an acronym for Secure Sockets Layer, a global standard security technology developed by Netscape in 1994. SSL is all about encryption. It creates an encrypted link between a web server and a web browser. The link ensures that all data passed between the web server and browser remains private and secure and is recognised by millions of consumers by a secure padlock which appears in their browser.

The SSL protocol is used by millions of e-Business providers to protect their customers ensuring their online transactions remain confidential. In order to be able to use the SSL protocol, a web server requires the use of an SSL certificate. Certificates are provided by Certification Authorities (CA) who in most cases also offer additional products and services to aid e-Businesses to demonstrate that they are trustworthy. Consumers have grown to associate the 'golden padlock', that appears within their browser display, as an indication of trust in the web site. This simple fact allows e-Business providers an opportunity to leverage that increased trust level to turn visitors into paying customers - so long as you know which type to choose.

source: whichssl