title: What do GCS bucket permissions 'All Users' and 'All Authenticated Users' and the groups mean?
body: <p>I have created a bucket for my Google cloud project, that has default permissions for 'All Users', 'All Authenticated Users' and 3 pre-defined groups. What do all these mean? </p>
  
  <p>I want to give read permissions to the objects inside the bucket to all (public) and write to bucket permissions to only my application and application editors. How do I do that?</p>