Hello bivector forum!

I’m an enthusiastic beginner when it comes to PGA and I have a basic comprehension question about the ‘May The Forque Be With You’ guide (May the Forque Be with You!):

I just don’t understand what is meant by the derivative of the motor. If the motor represents the current position and orientation, wouldn’t the derivative of the motor be a velocity? If so, what would be the difference between the bivector representing the velocity and the derivative of the motor? I’m just trying to somehow link this concept to my basic understanding of position/velocity, if that’s even possible.

I would appreciate if someone here could explain this to me (in simple terms would be nice). Thank you!