Bar charts visualize
numeric values grouped by categories. Each category is represented by one bar with a height defined by each
Bar charts are well suited to compare values among different groups e.g. number of votes by parties, number of people in different countries or GDP per capita in different countries. Bar charts are a bit spacious and work best if the number of groups to compare is rather small.
Below you can find an example showing the number of people (in millions) in the five biggest countries by population in 2007: