Managed plug-ins are managed .NET assemblies that are managed outside of Unity and compiled into dynamically-linked libraries (DLLs). For information about how to create and use managed plug-ins, refer to Managed plug-ins.
The IL2CPP scripting backend exposes the same .NET API surface as the Unity Editor and standalone Player. As a result, you can use the same plug-ins and you don’t have to compile separate versions to target different .NET APIs for Universal Windows Platform (UWP).