DC is super weird that way... The actual velocity of an electron down that line is, offhand, extremely slow compared to the speed of light.

Think of DC more like you're trying to pump a frozen ice mixture drink (trying to avoid any of the major brand names) down a straw. If you melt it, that's loss to heat. If the pressure gets there that's DC current.

The AC vibrations are the same thing except it's like the lever action on a steam locomotive. Translating the motor's spin into a back and forth wave in the line.

This is why AC is rather useful for making other things spin or vibrate to the point of being emissive.