What is the difference between 'Groups audience' and 'Groups content visibility' in Organic Groups Access? I am trying to set up Organic Groups Access for an existing site where I want to add gated content. I was watching this tutorial about setting it up, and it briefly addressed it. They said that 'audience' is better for sites where you have a bunch of existing nodes. Can someone give me a more technical answer, indicating what exactly the difference is?
Group audience = which group(s) content was posted to.

Group content visibility = who can see the posted content, only group members or all site users.

Do contact the author directly to ask them and/or let them know that the tutorial could be improved.