The definition and use of Presentation Manager resources by applications was mentioned in The Presentation Manager Application Model. The use of such resources greatly simplifies the task of the application developer in creating windows, menu bars, etc., and provides a powerful tool for the externalization of the user interface properties of an application object, thereby enabling easier modification of these properties during development or maintenance of the application. This chapter will describe the definition of resources, and the ways in which resources may be used within a Presentation Manager application.