common fraction vs fraction

common fraction and fraction both are nouns.

Word	Noun	Adjective	Verb	Adverb
common fraction	Yes	No	No	No
fraction	Yes	No	Yes	No

As nouns, fraction is a hypernym of common fraction; that is, fraction is a word with a broader meaning than common fraction:

common fraction (noun)	fraction (noun)
the quotient of two integers	a small part or item forming a piece of a whole
	the quotient of two rational numbers
	a component of a mixture that has been separated by a fractional process

common fraction (verb)	fraction (verb)
	perform a division