title: Can OS (iOS, Android, macOS, Windows) Read type of data being uploaded by Applications (even if encrypted)
body: <p>Not a super technical person here (just T-SQL programmer). I'm writing a original novel for  and like to put as much realism as possible based on current real technology.</p>
  
  <p>Can Operating systems whether personal computers or mobile devices able to read the type of data being uploaded by a third party application to the cloud or via bluetooth? If so how is it done the background behind it? what if the upload is encrypted (E2E)?</p>
  
  <p>Thanks!</p>