Binding components to variables

Variables are mechanisms for storing data needed by the framework at run time. Variables have two important attributes that control the life span of their values and their visibility:

Variable attribute	Description
Global	A global variable is available to all forms in the application. A nonglobal variable (also called a form variable) is available only to the form for which it was created.
Persistent	Persistent variables maintain their values across executions of the form (for form variables) or the client application (for global variables). Nonpersistent variables do not have to be explicitly created. The framework creates them automatically as they are referenced.