A PSO is a password policy that is available in a Microsoft Windows Server 2008 Domain Controller. It is more granular than Active Directory group policy because it is applied to a particular user or group. Group Policy Objects (GPO) sre applied to an entire organizational unit (OU). You may try to apply several PSOs to a person, but one will take precedence. The one with the lowest number will be the policy applied. To use the features in this video, you must promote your domain to a Server 2008 level.