illusion vs appearance

illusion and appearance both are nouns.

Word	Noun	Adjective	Verb	Adverb
illusion	Yes	No	No	No
appearance	Yes	No	No	No

As nouns, appearance is a hypernym of illusion; that is, appearance is a word with a broader meaning than illusion:

illusion (noun)	appearance (noun)
the act of deluding; deception by creating illusory ideas	the act of appearing in public view
an illusory feat; considered magical by naive observers	formal attendance (in court or at a hearing) of a party in an action
something many people believe that is false	pretending that something is the case in order to make a good impression
an erroneous mental representation	outward or visible aspect of a person or thing
	a mental representation
	the event of coming into sight