helping vs serving

helping and serving both are nouns.

Word	Noun	Adjective	Verb	Adverb
helping	Yes	No	No	No
serving	Yes	No	No	No

As nouns, helping and serving are synonyms defined as:

helping and serving: an individual quantity of food or drink taken as part of a meal

Other synonyms of helping include portion.

helping (noun)	serving (noun)
an individual quantity of food or drink taken as part of a meal	the act of delivering a writ or summons upon someone
	an individual quantity of food or drink taken as part of a meal