Explanation/Reference:
Explanation:
Set-GPPermission grants a level of permissions to a security principal (user, security group, or computer) for one GPO or all the GPOs in a domain. You use the TargetName and TargetType parameters to specify a user, security group, or computer for which to set the permission level.
-Replace <SwitchParameter>
Specifies that the existing permission level for the group or user is removed before the new permission level is set. If a security principal is already granted a permission level that is higher than the specified permission level and you do not use the Replace parameter, no change is made.
Reference: http://technet.microsoft.com/en-us/library/ee461038.aspx