written symbol vs graph

written symbol and graph both are nouns.

Word	Noun	Adjective	Verb	Adverb
written symbol	Yes	No	No	No
graph	Yes	No	Yes	No

As nouns, graph is a hyponym of written symbol; that is, graph is a word with a more specific, narrower meaning than written symbol:

Other hyponyms of written symbol include mark, character, grapheme, graphic symbol, phonogram.

written symbol (noun)	graph (noun)
a written or printed symbol	a visual representation of the relations between certain quantities, represented as points, plotted with reference to a set of axes
	a visual display of information
	a written symbol that is used to represent speech

written symbol (verb)	graph (verb)
	represent by means of a graph
	plot upon a graph