There are several levels or roles of users in the web site. Two are default Drupal user roles (anonymous and authenticated) and the others are custom roles created for this site.
User 1 is not a role, but rather the user with the ID of 1. It is the first user created in Drupal and has ultimate power and can do things that no other user can do. Usually the first thing User 1 does is to create a user role for administrators and grants them permission to do whatever is needed. This usually includes the ability to modify user roles and permissions.
There is kind of an inheritance with roles in that a user can simultaneously be anonymous, authenticated and be zero or more other roles at the same time.
This means that if a permission is applied to the anonymous role it need not be applied to any other because all users and non-users are anonymous. And any permission applied to the authenticated role need not be applied to any other role because any authenticated user falls into that role.
The administator is not a special user role (like User 1) but one created for this site so that many people can administer this site.
Administrators can perform any task on the site because then have the ability to change role permissions and can grant any permission to their role.
Administrators are meant to be the technical people who understand how the Drupal site works and can perform administrative tasks.
The cabal role is reserved for those special shadowy users who administer the FLOSS fund. They should have the ability to edit and delete any nominee node.
A host is an emcee or a person that takes care of meeting agendas. The host can create meeting agendas and presentations.
A librarian is a user who administers the library or books and DVDs. Currently there are no permissions assigned to librarians.
A member is a generic user that has been approved. The member can create blog posts, forums posts and post other content.
A speaker is one who delivers a presentation. The speaker can create and edit any presentation content.