ASCII character vs graph

ASCII character and graph both are nouns.

Word	Noun	Adjective	Verb	Adverb
ASCII character	Yes	No	No	No
graph	Yes	No	Yes	No

As nouns, graph is a hypernym of ASCII character; that is, graph is a word with a broader meaning than ASCII character:

ASCII character: any member of the standard code for representing characters by binary numbers
graph: a written symbol that is used to represent speech

Other hypernyms of ASCII character include character, grapheme, graphic symbol.

ASCII character (noun)	graph (noun)
any member of the standard code for representing characters by binary numbers	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

ASCII character (verb)	graph (verb)
	represent by means of a graph
	plot upon a graph