Illusion is a distorted or distorted perceptual experience that does not conform to the characteristics of the stimulus itself  In life, the interpretation based on perceptual experience is obviously distorted or even wrong  Hallucinations are unreal perceptions that occur without the direct action of the corresponding external objective things  Illusion has characteristics similar to real perception, but it is illusory  Normal people may experience hallucinations in certain special states, such as intense emotional experience accompanied by vivid imagination, memory, or anticipation, nervous emotions, or in a hypnotic state
Hallucinations can also occur during sleep or waking states
Your figure still appears in front of my eyes all day long, and your voice still echoes in my ears