Android : In the OpenRTB bid requests, is "bundle" unique to an app?

I am looking at multple openRTB specs, for example from MoPub. They have a bundle field in their bid request. Bundle is a number 123456 for an iOS app, or package name for an android app like package.bundle.apname. Is this "bundle" unique to an app?

1. 
   

   Can a single app have multiple "bundle"?

   
   


2. 
   

   Can a single "bundle" might mean multiple apps?