penny vs cent

penny and cent both are nouns.

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

As nouns, penny and cent are synonyms defined as:

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

Other synonyms of penny include centime.

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