The "Build" number in your file indicates it is part of a series of technical refinements. These updates often add:
: Centers on the rise of the Babylonian Empire. File: Age.of.Empires.Definitive.Edition.Build.3...
The definitive edition includes all original campaigns and those from the Rise of Rome expansion, focusing on the growth of legendary empires: The "Build" number in your file indicates it
: Follows the rise of the Greek city-states and the conquests of Alexander the Great. File: Age.of.Empires.Definitive.Edition.Build.3...
: Refined scenario descriptions and more accurate geographical names compared to the 1997 original.
: A tutorial campaign tracing the early development of Egyptian civilization.
: All unit voices were redone for this edition, and cinematic cutscenes were added to enhance the narrative.