It's estimated that Google+ has about 25 million users, while Facebook has in excess of 750 million.

Another change Facebook is introducing is allowing users to modify the audience of a post after it's published, which they couldn't do before, the company said.

Facebook is also introducing a review period for photos and posts in which users are tagged, giving the tagged users a chance to review the photo or post before it's displayed on their profile, in case they want to un-tag themselves.

A feature Facebook has had for years, which lets users see how their profile looks to another user, is gaining a more prominent placement in the profile page to make it more easily accessible and promote its usage.

Along with the privacy-awareness changes, Facebook is also expanding users' ability to tag others and label posts with geographical locations.