After migration blank screen

Thank you @israel.cefrin, I just don’t understand what the ‘correct’ file and folder owning would be. At FAQ Permissions it says:

The ownership of cache, public, and other web-writable directories should be your web user and the web-user’s primary group, for example apache:www-data. Permissions should probably be 750. The ownership of the other non-web-writable directories should be your user, with either the web user’s group, or with public execute permissions.

  1. Who is my ‘web user’?
  2. Why does the FAQ say that the permissions should ‘probably’ be 750? Is the author not certain, or are there circumstances under which they should be something else?
  3. Is ‘your user’ different from ‘your web user’?

I now want to install OJS 3 and don’t want to get into trouble again with ownerships and permissions. Thank you, Daniel