So, if you're a Windows 10 Insider who's keeping track of such minutia as how quickly build numbers are incrementing, you might have gotten the impression that build 14251 should be significant because it's so much higher than 11102, or even 11107. Not so fast, Microsoft wants us to know.
While we'd love to think that we can measure the significant of a build by its sheer numerical value, that's not the case:
Sharp-eyed Insiders likely noted the big jump in build numbers from our last preview build (11102). Historically, the codebase for mobile had a different OS version than the codebase for PC because they were developed by different teams on different schedules. With Windows 10, we became one Windows team and brought these two codebases together. We started by changing the version string displayed in the UI to be consistent, which is why you saw similarly labeled builds over the past year for both Mobile and PC, but the underlying binary version numbers were still different. As part of our work getting the common codebase ready for the next release, we decided to complete that work and sync the build numbers between mobile and PC. Because the mobile codebase used higher build numbers than PC, we needed to jump ahead a bunch of build numbers to ensure updates to future builds will continue to work. So that’s why build numbers went from 11105, 11106, and 11107 to 14251.
Operating system development is a strange world for sure, and we're only getting such glimpses into its nuances because Microsoft has opened things. The Windows Insiders program is therefore not only a way to get access to new Windows 10 bits much sooner, but also to peek into a world that we'd otherwise never see.
That said, we're glad for the clarification. So, if you're an Insider, don't expect too much given the big jump in build number. That is all.