Sony does iterate...this is the 4th iteration of the Z series I believe the author is delineating between "iterating" being small improvements to a relatively

Sony does iterate...this is the 4th iteration of the Z series I believe the author is delineating between "iterating" being small improvements to a relatively static product as opposed to "versioning" which are fairly significant changes between releases. Compare the 2008 MacBook Air 1 to the 2011 MacBook Air 4.