displays one of a number of components, typically JPanels, in a way that's
comes from thinking of the individual panels as cards that are in a pile,
where only one of them is visible on top at one time.
Program, not user, control.
The selection of which panel to display is completely under program, not user,
JTabbedPane is often a better choice because it is
better to give the user control.
However, there are places where
CardLayout is typically
used where the user control is achieved by other means.
are often implemented using a
which is controlled by Next and Previous buttons.