The document/view architecture divides a program into four main classes: the document class stores the program's data, the view class handles displaying data and user interaction, the frame class contains UI elements like menus and toolbars, and the application class starts the program and handles Windows interaction. Documents represent the data, views provide interfaces to interact with documents, and the frame and application classes manage the overall application. This architecture provides reusable code, separates program responsibilities, and allows flexible user interfaces.