astronomer vs Giovanni Schiaparelli

astronomer and Giovanni Schiaparelli both are nouns.

Word	Noun	Adjective	Verb	Adverb
astronomer	Yes	No	No	No
Giovanni Schiaparelli	Yes	No	No	No

astronomer (noun)	Giovanni Schiaparelli (noun)
a physicist who studies astronomy	Italian astronomer who first noted lines (which he called canals) on the surface of Mars (1835-1910)