cent vs penny

cent and penny both are nouns.

Word	Noun	Adjective	Verb	Adverb
cent	Yes	No	No	No
penny	Yes	No	No	No

As nouns, cent and penny are synonyms defined as:

cent and penny: a coin worth one-hundredth of the value of the basic unit

Other synonyms of cent include centime.

cent (noun)	penny (noun)
a coin worth one-hundredth of the value of the basic unit	a coin worth one-hundredth of the value of the basic unit
a fractional monetary unit of several countries	a fractional monetary unit of Ireland and the United Kingdom; equal to one hundredth of a pound