Question

Difference between electrical signal and electromagnetic signal

Answer 1

Electromagnetic signal:
electrical wave and magnetic wave (bundled together with same frequency and amplitude) oscillating in mutually perpendicular direction, orthogonal to the direction of propagation of the signal. Does not need a medium for propagation.
eg: light, heat, gravity etc



Electric signal:
Any signal, light/sound/video that is sent over a wire (conductor) by drifting of electrons in it (current) caused variation of electrical voltages at either end. They need a conductor to propagate. eg: Electricity coming to your house, or the music from your cellphone, through the earphone wires.