a. an understanding of relationships that sheds light on or helps solve a problem.
b. (in psychotherapy) the recognition of sources of emotional difficulty.
c. an understanding of the motivational forces behind one's actions, thoughts, or behavior; self-knowledge.
It makes Firebug know about ExtJS components and it's an absolute gem.
In this screenshot from Steven's blog you can see the Ext components on the left, and their properties etc on the right.
Currently it supports ExtJS, Sencha Touch, Dojo, SproutCore with plans for qooxdo, jQuery UI and YUI.
It's early days for it's development, and it will be a commercial product, but looks like a great addition for your toolbox.
BTW, I have no affiliation with the product and don't know Steven. I'm just impressed with the concept.