What is the difference between being "Supervisor" and "Visitor" for a Group manger (admin)?

More than one managers can access the same group with two different levels of rights:

• as "Supervisor" of the group: he/she then has all the rights to manage and lead the group. The supervisor is authorized to access the Group Dashboard, add or remove drivers, pass messages, access the profile of a driver belonging to the group or organize a driving challenge for the group;
• as a "Visitor" to the group: in this case, the manager has limited rights and is only allowed to view the Group Dashboard. The visitor will not be able to access the profile of a particular driver.