Electronic Signals

An analog signal continually fluctuates in voltage up and down. But a digital signal has only a high or low state, corresponding to the two binary digits.
All electronic signals (both analog and digital) degrade as they move down a line. That is, the voltage of the signal fluctuates due to environmental effects.

An analog signal continually fluctuates in voltage up and down. But a digital signal has only a high or low state, corresponding to the two binary digits.