There are five basic WordPress roles of relevance to FVT. These can be assigned when users are created or changed later on by anyone with Administrator capabilities.

WordPress documentation on roles and capabilities goes into much more detail. Key points:

• Subscribers: Can’t do anything except edit their own profiles, and view the site like other people.
• Contributors: Subscriber capabilities + can draft and edit their own posts, pages, biographies, and events.
• Authors: Contributor capabilities + can independently publish their own posts etc.
• Editors: Author capabilities + can independently edit and publish other people’s posts.
• Administrators: Editor capabilities + can adjust all administrative settings.