HTTPS vs HTTP
Why use HTTPS?
Web browsers such as Internet Explorer, Firefox and Chrome also display a padlock icon in the address bar to visually indicate that a HTTPS connection is in effect.
All communications sent over regular HTTP connections are in ‘plain text’ and can be read by any hacker that manages to break into the connection between your browser and the website.
I strongly recommend that if your are paying online on any website or sending confidential information (even when you are at home) you should verify that the site uses HTTPS before considering to use it.
I have spared you the details of how encryption actually works for now (public and private keys!)!