bar chart vs graph

bar chart and graph both are nouns.

Word	Noun	Adjective	Verb	Adverb
bar chart	Yes	No	No	No
graph	Yes	No	Yes	No

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

Other hypernyms of bar chart include chart.

bar chart (noun)	graph (noun)
a chart with bars whose lengths are proportional to quantities	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

bar chart (verb)	graph (verb)
	represent by means of a graph
	plot upon a graph