simple fraction vs fraction

simple fraction and fraction both are nouns.

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

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

simple 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

simple fraction (verb)	fraction (verb)
	perform a division