Access
Required access: Manage access to this item towards the unit you are editing; Manage user's access rights towards the users in the left part of the dialog.
On the Access tab of the Unit Properties dialog you can indicate which access rights different user have towards the unit.
The list of users whose access can be changed is displayed on the left. The users with the colored background at the top of the list are those who already have some access to this unit.
On the right, the list of both standard and special access rights is displayed where the allowed actions are checked.
Read more about the access rights here.