인간 = human being (when talking about humans as a category or a person as a human being) 사람 = human, Man (with a capital "M"), a person (or people, in general) 인물 = personhood, personage (considering a person as a product) -- as in the English word "personage" it has a positive connotation, e.g., an important/prominent person, a person with talent, or even a particularly handsome person.