Put at its most very, very basic, a dynamic works like a louspeaker in reverse - i.e. a coil moving through a magnetic field, actuated via air pressure on a diapraghm, generates a signal which is then amplified - whereas a condenser works like a capacitor - as in, the capacitance of two closely spaced plates varies based on their physical distance from one another (which varies by air pressure on one of the plates) , and that varying capacitance is amplified and becomes the signal.
So it's a completely different - completely different - method of producing a signal, which therefore has different characteristics and physics.