title: Xamarin Shared Library and PCL
body: <p>What is the exact difference between xamarin shared project and portable class library?</p>
  
  <p>When to use shared library and when to use portable class library?</p>
  
  <p>Is this possible to write native functionality in shared projects like showing alert,accessing camera and use it for both android and iOS?</p>
  
  <p>Can anyone please explain me.</p>