Hi Max,
Phase Response, Group Delay and Phase Delay all these terms carry different meanings.
The relationship between the phase of input signal and processed output signal is known as phase response.
A signal can contain multiple sinusoidal components. The time delay of amplitude envelopes of these sinusoidal components is called group delay, whereas,
The time delay of phase of various sinusoidal components present in a signal is called Phase delay.
Hope it helps.
