The FRAME control is used to group together one or more controls. The outer most FRAME defines a form or dialog.Frames can also be used to build complex sub-components of a form.
By grouping together two or more controls into a frame and by having several such frames sit in the same position on a form, it is possible to selectively enable and disable (make visible and invisible) groups of controls.
It is also possible to set up complex sizeing constraints.