demon vs ogre

demon and ogre both are nouns.

Word	Noun	Adjective	Verb	Adverb
demon	Yes	No	No	No
ogre	Yes	No	No	No

As nouns, demon and ogre are synonyms defined as:

Other synonyms of demon include devil, fiend, monster.

demon (noun)	ogre (noun)
an evil supernatural being	(folklore) a giant who likes to eat human beings
a cruel wicked and inhuman person	a cruel wicked and inhuman person
someone extremely diligent or skillful