Group Policy is a feature of the Microsoft Windows NT family of operating systems that control the working environment of user accounts and computer accounts.
Group Policy provides an infrastructure for centralized configuration management of the operating system and applications that run on the operating system.
Group Policy is an infrastructure that allows you to implement specific configurations for users and computers. Group Policy settings are contained in Group Policy objects (GPOs), which are linked to the following Active Directory directory service containers: sites, domains, or organizational units (OUs). The settings within GPOs are then evaluated by the affected targets, using the hierarchical nature of Active Directory. Consequently, Group Policy is one of the top reasons to deploy Active Directory because it allows you to manage user and computer objects.