Born in 2011 as an experiment, Google Authorship was that functionality that allowed the authors of content to identify themselves for display purposes.
After one year from its implementation, in 2012 many authors used it but the percentage of users that adopted the solution, was not satisfactory to consider it as a useful functionality according to Google engineers.
For this reason Big G decided to end its three-year experiment.
Author Rank and Google Authorship are different things, even if Authorship doesn't exists anymore you can use Author Rank instead, Google ranking system and its algorithm consider it for "evaluating and trusting" authors on the net.
For this reason you can still see some author faces on the SERP, those are the "trusted" authors of a specific argument.
This is just one of the SEO elements that Google uses for indexing, an element that shoudn't be ingnored.
In my next article I will teach you some tips and tricks to follow for a good reputation and quickly became a "Guru" for Google.