The Toolkit provides a set of user interface objects called widgets . Widgets are the building blocks for the user interface of an application. Because the Toolkit implements widgets with a consistent appearance and behavior, users can move between DECwindows applications without having to learn how to use a new interface. From a programmer's perspective, widgets are windows that are logically connected to application functions. A Toolkit widget is made up of a window packaged with input and output capabilities.
Some widgets display information, such as text or graphics.
Others are merely containers for other widgets. Some widgets are for output only and do not react to pointer or keyboard input. Others change their display in response to input and can invoke functions that an application has attached to them. Some widgets in the Toolkit have variants, called gadgets . Gadgets have the same general appearance as their widget counterparts but have restricted capabilities.