This is an electronic informatics concept
Pulse is pulsation, impulse is impact, pulse signal is pulsating impact signal, referred to as pulse signal.
In a broad sense, all signals with periodic changes except DC signals and sinusoidal signals can be called pulse signals, because it always appears the same situation every once in a while, just like the pulse of biology, periodic changes, so it is called pulse signals.
In a narrow sense, only rectangular wave signals are called pulse signals. Pulse signals have three basic properties: amplitude, width and density. The process of making at least one property of the pulse signal change with the desired regularity is called modulation. The signal obtained after modulation is called pulse modulated signal.
Common modulation modes are: PAM (pulse amplitude modulation), PWM (pulse width modulation), PDM (pulse density modulation). Because the signal amplitude is easily affected by external interference, the latter two modulation methods are commonly used.