Compound
It is possible to split each column into sections to show the breakdown of data. For example, the employment data shown on the previous page could have been represented as three columns on a bar chart. The three columns would represent the three countries, with each column subdivided into sections showing primary, secondary and tertiary in different colours. This type of bar chart is sometimes called a compound bar graph.
Comparative
It is also possible to compare two sets of data on a bar graph - for example, measuring rainfall in two countries over the same period. This type of bar graph is called a comparative bar graph.
The chart below compares the tourism data for the UK in October 2001 with October the previous year. The graph shows how tourism declined after the terrorist attack in America in September 2001.