profit sharing vs percentage

profit sharing and percentage both are nouns.

Word	Noun	Adjective	Verb	Adverb
profit sharing	Yes	No	No	No
percentage	Yes	No	No	No

As nouns, percentage is a hypernym of profit sharing; that is, percentage is a word with a broader meaning than profit sharing:

profit sharing: a system in which employees receive a share of the net profits of the business
percentage: assets belonging to or due to or contributed by an individual person or group

Other hypernyms of profit sharing include part, portion, share.

profit sharing (noun)	percentage (noun)
a system in which employees receive a share of the net profits of the business	assets belonging to or due to or contributed by an individual person or group
	a proportion in relation to a whole (which is usually the amount per hundred); ten percent