Roles vs Roles & Subordinates

Roles vs Roles & Subordinates

Could someone please explain to me the difference betweens Roles and Roles & Subordinates?

When creating Groups, we are given the choice to add Users, Roles, Roles & Subordinates or pre-existing Groups.

If I have a tree of Roles set up this way, for example:

- CEO
   -  Manager
        - Employee level 2
            - Employee level 1

If I create a new Group A, and add "Manager" to it as a Roles & Subordinates (as opposed to just a Role), does it add everyone starting at the Manager level and down?