Java graphics - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 164

Figure 6.2 This diagram shows a subset of the components in the Swing class
hierarchy. Light gray indicates classes from the java.awt package, dark gray classes
from javax.swing .
provide instructions on how to set up the HTML for applets so that the browser
will download an up-to-date Java Plug-in. The plug-in brings the Java support
up to the current 1.4 or 5.0 level but requires a large download the first time it is
used (then it is cached for later use). The long initial download can be a problem
for users on slow connections. Another promising trend is that many desktop
computer manufacturers (including Dell and HP) now include a recent version
of the JRE and Java Plug-in with their Windows operating systems.
6.5 Containers
Container components can, as the name implies, hold other components. The
sub-components can be atomic components that serve a single purpose, such as
abutton, or they can be containers themselves.