On the web, you can tack an “s” onto the “http” at the beginning of many web addresses to make your browsing more secure. It’s a simple idea and a great habit to pick up.
The s in the Web address indicates that you’re using a secure layer. It means that you are transmitting securely. It does not mean that either your computer or the computer with which you’re communicating are secure. When you type a search into Google and click on a result, you may not be leaving the protection of the encrypted Google search.
Get the full story at this slaw.ca blog post.