Hypertext Transfer Protocol Secure (HTTPS) is a combination of the Hypertext Transfer Protocol with the SSL/TLS Protocol to enable data encryption and secure identification of the given server. Facebook on Wednesday provided an option to users whereby the feature can be made available as the default connection for everything done on Facebook, as against the former usage only when an account is accessed outside Facebook through Facebook Connect.
The feature is especially useful when a user is uncertain about the security of a network or computer, that is to say that access to the internet is gained on a public Wi-Fi hotspot or a public computer. The key part of gaining control over ones personal information has always been to protect it from hackers, malwares and viruses.
A secure connection, however is indicated when the small 'lock' icon on the browser address bar turns green, which indicate that your browser is using a secure connection (HTTPS) to communicate with the website.
Application developers on the other hand, are required to use a secure canvas URL, so that the apps can also be accessed over HTTPS. Further information on the guidelines for developers wishing to incorporate HTTPS to their applications are available through this link.
However, the option exists as an advanced security feature, and therefore requires to be activated by user before it is implemented. The activation option can be found in the 'Account Security' section of the 'Account Settings' page.