What is the terminology for panel/frame "sliders"?

["Daniel B. Thurman" <dant cdkkt com>]

I am not well versed in windows terminology,
so what do you call the "slider" that allows
panels or frames to be resizeable?

For example:

         V-Slider:
             v
+===========+v+===========+
|           | |           |
|           | |           |
|           | |           |
|           | |           |
|           | |           |
|           | |           |
+===========+ +===========+
>        H-slider         <
+=========================+
|                         |
|                         |
+=========================+

It's not a scrollbar, or so I think, but it
allows for either panels to grow or shrink
depending on which slider is chosen and in
which way one slides it.

So what widget can I use for this and what
is it called?

Thanks!
Dan