The tenant admin can view and manage tasks on all tenant users' task lists. Users, other than the tenant admin, can be designated as flow admins for each flow by the designer. Designating flow admins ensures that more than one person can manage tasks.
For example a vacation request form might be on a manager's task list waiting for approval but the manager it not available to approve that request. The tenant/flow admin can login and view the manager's task list and reassign that task to another person. See the Modify a Task topic in the List documentation chapter for more information.