When you allow someone to look at the resource you grant them see and view access, when you allow someone to change the resource they get see, view and edit access.
Use the - buttons to remove groups, the + button to add groups and the * buttons to change the access rights for members of a group. Changes are immediate.
If the option to apply the access control of the containing resource is selected the access control here is also applied. I.e. control is additive. In particular members of the owners group will retain manage access even if they are denied this access in the containing location.
In addition to access rights set in the table above system policy rights also apply.
