histogram vs bar chart

histogram and bar chart both are nouns.

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

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

histogram: a bar chart representing a frequency distribution; heights of the bars represent observed frequencies
bar chart: a chart with bars whose lengths are proportional to quantities

Other hypernyms of histogram include bar graph.

histogram (noun)	bar chart (noun)
a bar chart representing a frequency distribution; heights of the bars represent observed frequencies	a chart with bars whose lengths are proportional to quantities