Difference between hallucination and illusion

I was in illusion about illusion and hallucination until recently i discovered the difference between the duo.
Both are perceptual disorders
In illusion - misinterpretation of the actual stimulus eg. Seeing rope as a snake
In hallucination perception occurs in the absence of any stimulus eg. Able to see snake without any rope or the typical 3rd person auditory hallucinations charectetstic of Schizophrenia