Bar graph means: Bar graph: Visual display that uses bars to show the relative sizes of various categories of variables. Each category of the variable is represented as a bar with an area between them. Bar graphs are often used to show the main features of distribution of data. They can be easier to understand and comprehend the information. A bar graph is often used in medicine. A bar chart is also known.
(in Medical Dictionary)

What else does Bar graph mean?

A graph that consists of horizontal bars, or rectangulars. The length of the rectangles is proportional to how often specified numbers occur within a given set of data.
(in Merlin Dictionary)