title: what is a non-SDK interface
body: <p>After searching new Android P features, I came across the non-SDK interfaces restriction. and my question is,</p>
  
  <p>What is a non-SDK interface or an SDK interface?
  What is the difference between them? specially that makes non-SDK once better.
  Examples of popular SDK and non-SDK interfaces available for android.</p>
  
  <p>P.S. I came across abstract answers differentiating between SDK and API interfaces but it didn't fulfill my questions :/</p>