Roles lists the Topic's roles, with each role's Topic permissions across the page.
Built-in roles
Owner - every permission. There's always exactly one Owner role.
Topic Admin - can't be deleted; adjust its permissions as you like.
Your own roles
Add a role, name it and describe it. Rename inline; delete ones you don't need.
Topic permissions
Each role can be given permissions such as designing the Topic, managing its people, creating items, exporting, or seeing reports. Tick what each role needs and nothing more.
Make many roles at once
The role generator creates roles from a tree's tags: for example, a Manager role for every value tagged Office, each scoped to its own office. It saves a great deal of clicking for organisations with many sites.