Permissions allow you to define four specific roles and define which team embers can do and see what. The four different roles are the following:

Owners: Owners have all the permissions, including managing permissions and deleting/duplicating the task/group the current permission is set on. Workspace administrators always have this role anywhere.
Managers: Managers have all the permissions except managing permissions and deleting/duplicating the task/group on which the current permission is set. Owners can't be defined as Managers as their role already allows these permissions.
Workers: Workers represent users that can be assigned tasks (either automatically predicted or forced). They can modify the status, efforts, time worked, descriptions, add files, comment, and follow/unfollow tasks. Be aware that even if a user is defined as an owner or manager, he isn't automatically a worker, meaning that he will be able to see and modify tasks but not be assigned to them.
Viewers: Viewers can only see tasks, add files, comment, and follow/unfollow tasks. Owners, Managers, and Workers can't be defined as Viewers as their role already allows these permissions. This is the ideal role to give to your customers or partners and have them have a view of their projects, for example.

Insights Permissions