At the end of the book, it also briefly delves into the New 52 continuity.
The Superman Files attempts to chronicle the Modern Age version of Superman, but in the modern age there have been three contradictory accounts given for Superman's origins, given in The Man of Steel, Superman: Birthright, and Superman: Secret Origin.
This book reconciles the events of all three accounts into one coherent story.
The book was published in 2013, two years after the "New 52" reboot, and despite that the primary content of the book chronicles Superman's history in the previous continuity.
Despite this, the book does feature a brief section at the end on the events of the New 52 continuity.