SSL

What does SSL mean? Well, to begin, it stands for Secure Socket Layers and it is basically what makes secure sites secure. Here's how it works.

When you log into a secure server, it communicates with your Web browser for a few seconds. During this communication, it sends your browser encryption information, that only it and your browser can read, out. Once this encryption is set, it acts like a normal Web page, except that all the information coming or going is encrypted. This encryption makes it extremely difficult for any third party (anyone who would intercept the transaction) to decipher it. All this extra protection is why secure servers seem to run slower than their unsecured counterparts.

Secure connections only protect the information as it's coming and going, not when it's just sitting on the server. With that being said, you probably have a better chance of getting ripped off by a sales clerk copying your credit card number at a department store than getting your information stolen over the Internet. Also, you can tell if a site is secure by the first part of its Web address. If it starts with https:// rather than http://, it's secure as can be. Stay safe!

~ Quoted from Steve