City of Light vs Paris

City of Light and Paris both are nouns.

Word	Noun	Adjective	Verb	Adverb
City of Light	Yes	No	No	No
Paris	Yes	No	No	No

As nouns, City of Light and Paris are synonyms defined as:

City of Light and Paris: the capital and largest city of France; and international center of culture and commerce

Other synonyms of City of Light include capital of France, French capital.

City of Light (noun)	Paris (noun)
the capital and largest city of France; and international center of culture and commerce	the capital and largest city of France; and international center of culture and commerce
	a town in northeastern Texas
	(Greek mythology) the prince of Troy who abducted Helen from her husband Menelaus and provoked the Trojan War
	sometimes placed in subfamily Trilliaceae