Why the AWT components are called heavy-weight and SWING as light-weight?

Question

Why the AWT components are called heavy-weight and SWING as light-weight?.
Building our own components means overhead on JVM. hence in what sence the SWING components are called light weight.?
I know that the Swing componets are the components which are not going to depend upon peer classes and render, OS independent LOOK n FEEL.
Thanks,
Sanath Kumar

Answer 1

All extensions of Component are considered lightweight since, as you point out, they don't have their own dedicated native peer.
Essentially a lightweight component only has a canvas on which to draw itself and some means of receiving events from the system. In fact, there is no need to have one of these "canvas" and "event" objects for each component - the parent component can manage these abilities on behalf of its children. Eventually you end up with only top-level components needing to be heavyweight in order to communicate with the windowing system.
A lightweight component therefore has the minimal dependency on the underlying windowing system giving you maximum cross-platform flexibility.
It is usually true that lightweight => slower and heavyweight => faster since it is reasonable to assume that native peers will be optimal for the windowing system. However, that's not the point of the lightweight/heavyweight distinction.
Hope this helps.