I'd be happy to. First off, all motor points are pressure points, but not all pressure point are motor points. Pressure poins can be found all over and mostly consist of areas where you can apply painful pressure to muscles, muscle-like fibers (tendons, etc), veins and arteries, and nerves. When we start talkg motor points, we are in fact talking about specific nerve centers.
The main difference between motor points and pressure points is that pressure points rely on pain compliance due to constant or dynamic pressure. Motor points do not.
Case in point - The Brachial Plexus
http://upload.wikimedia.org/wikipedia/commons/3/3a/Gray808.png
This nerve plexus has its origin at the stem of the brain and is responsible for all the nerve signals that run to your arm. If you think of it as a tree, then the brachial plexus is the trunk, the suprascupular, radial, ulnar, and median nerves are all brances. You can attack each of these brances for pain compliance, but if you attack the nerves plexus proper, you can short out the entire network for a few seconds. My personal favorite applications are to strike where the plexus ties in to the shoulder joint (leaving the arm temporarily paralyzed), and to attack it at the origin proper. A strike to the Brachial Origin is enough to make your average person completely drop to the ground, and it will be a few minutes before they are back to normal.
Here is an example caught on TV of a martial arts instructor who teaches police defense tactics dealing with a pimp abosing one of his hookers.
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This video does not talk much about the nerves in that are, but instead talks about the veins and arteries that are grouped near it:
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For the record, I've never knocked someone out using this technique before, but I've also never wanted to. I've used it for demonstrations in the classroom, but I'm very careful with it. Even a simple slap with intent behind it will make you see stars.