When Microsoft announced that it would no longer be using the Metro branding, many were left wondering how Microsoft would refer to the apps in Windows 8. With Metro gone, the confusion quickly caused anguish among those working with the applications as how to properly refer to them in the public sector. Thanks to an interview Neowin conducted today with Soma Somasegar, we now have better clarity into how to properly distinguish between Modern Apps and Windows Store Apps.
In short, Modern Apps is a high level look at applications and does not refer to a single application but is the shell that some Windows Store apps reside. Modern App refers to how an application works and by Soma's definition, any application that spans multiple platforms (Windows 8 and Azure or Windows Phone and Azure, or Windows Phone and Windows 8) is considered a modern application. An application that only runs inside Windows 8's new Start screen, is considered a Windows Store App.
A Windows Store App is not necessarily a Modern App, an example of this would be any application that is standalone, such as Escapa. Escapa would be considered a Windows Store App, but not a modern App because it stands alone and does not depend on any other service to operate. If Escapa added functionality to have cross platform gaming, then it would be a Modern App too. Essentially, a Windows Store App can also be a Modern App too but not all Windows Store Apps are Modern Apps.
As Microsoft works to removed Metro from search engine results, they will replace it with Windows Store Apps and Modern Apps. Always remember that a Modern App is an app that spans Microsoft's ecosystems and Windows Store Apps are specific to the Windows Store.
If you have questions for Soma, he will be doing a Reddit AMA on Friday at 11:00am - Pacific.