What are the 5 types of hallucinations?

A hallucination is the perception of an experience which does not have confirmation in reality. The five types are:
•    Auditory hallucination: hearing things that have no external sound
•    Visual hallucination: seeing something that isn’t visible to others.
•    Olfactory hallucination: smelling something that doesn’t smell to others.
•    Gustatory hallucination: experiencing a taste, often an unpleasant one, that shouldn’t happen
•    Tactile hallucination: a false sensation on the skin