What is the difference between an Owner, Editor, and Collaborator?

Collaborators are able to:
1. Start Discussions
2. Create a Document
3. Invite Participants

Editor is able to:
1. Start Discussions
2. Create a Document
3. Create an Announcement
4. Create a Poll
5. Create Tag Groups

Owner is able to:
1. Start Discussions
2. Create a Document
3. Create an Announcement
4. Create a Poll
5. Create Tag Groups
6. Customize Layout
7. Create Sub Groups
8. Manage Group
9. Invite Participants
10. Invitation Status