bar chart vs bar graph

bar chart and bar graph both are nouns.

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

As nouns, bar chart and bar graph are synonyms defined as:

bar chart and bar graph: a chart with bars whose lengths are proportional to quantities

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