Difference between Windows Phone 8.1 and Windows Phone Silverlight 8.1

Question

I was reading about Windows Phone 8.1 Development, because I already work with Windows Phone 8 and I intend to start working with the new OS version.

Then I downloaded t

Answer 1

The main difference is that Windows Phone 8.1 Store Apps strictly use WinRT APIs which are not available under Silverlight.

Before you read on, this is the short version:

• Windows Phone 8.1 Store App code runs on all Windows Phone 8.1+ and Windows 8+ machines, since it uses the unified WinRT API.
• Windows Phone Silverlight App code runs on all Windows Phones 7+ but not on all Windows 8 machines (ARM machines do not support all features). That's why Windows Store apps are using different APIs (WinRT). You might want to check out this link: http://msdn.microsoft.com/en-us/library/windows/apps/jj681690%28v=vs.105%29.aspx

Windows Phones were using Silverlight apps only up to version 8 while apps for Windows 8 (an up) offered the WinRT API as well - you may have noticed the Windows 8 RT versions for ARM CPUs..

So - to stop the endless parallelism of Silverlight and WinRT Microsoft decided to unify the development process. Starting from Windows Phone 8.1, Windows Phone also runs WinRT (rebranded as Windows Runtime, I think) apps.

The main advantage is that you can now easily port Windows Phone 8.1 code to a Windows 8.1 app and vice versa, since both are using the same APIs. Accessing files, storage, networking.. it's all the same across Windows Phone and for Windows Store Apps.

This is where Universal Apps come into play. Instead of porting your code later by creating a new project you can now easily create a universal project that contains shared code both for Windows Phone 8.1 and Windows 8.1.

However, the downside is that your app won't run on Windows Phones < 8.1.