Before there was Build, there was PDC. Ten years ago, in 2009, Microsoft’s Professional Developers Conference was the place to be if you were building software for Microsoft’s platforms.
A decade later, PDC has been replaced by Build, which is different in much more than just the name and the fact that it occurs every May rather than sporadically in October-November. The biggest change is that the Build conference is no longer tied to the release of a milestone version of Windows.
Source: Microsoft Build 2019 preview: Azure is the star, and Windows is a bit player | ZDNet
