Erik....you are confusing an analog Class D amplifier with a CD player. Binary is a single term/method only of how a laser reads the pits on a compact disc. The space in between the pits are "bumps" results in reading pits,bump,pits,bump, 1,0,1,0,1,0.....switching only applies to switching transistors. Mosfet's are dual switching, moving current in both directions. Diode transistors move current in one direction. Just about all Class A/AB amps use switching transistors. Binary only applies to the digital domain and nowhere else. Nothing confusing about that.