How to use the Pen Palette?

Can anyone explain (perhaps a video tutorial) how to use the "Pen Palette" widget and toolbar?
I saw "sand1024"s video, but there is no spoken explanation. It's still confusing.

well, I suppose that widget is quite straightforward and I've illustrated the most of its functionality of it in that video...

In short - it's just a collection of named pens (where pens is a combination of line color, line type and line width).

You may define the pen and apply to entities, plus some additional functions available via menu (like selecting entities with specific pen, applying pen to selection, applying pen the active layer).

Basically, you can create such pens and reuse them between drawings.

In short - that's all, just a more effective manipulation of styling attributes, that is the most useful for drawings that contains lot's of elements, colors and line types/widths.  It might be also useful for simpler drawings too, yet there it is possible just to rely on pens that are assigned to layer.

So basically I'm not sure I understand what is confusing there, yet if you have some specific questions - I'll try to address them.

Okay, I see.
Your brief explanation really helps.
Thank you very much.