Bar chart

A bar chart or bar graph is a chart with rectangular bars with lengths proportional to the values that they represent. The bars can also be plotted horizontally.
Bar charts are used for plotting discrete (or 'discontinuous') data i.e. data which has discrete values and is not continuous. Some examples of discontinuous data include 'shoe size' or 'eye colour', for which you would use a bar chart. In contrast, some examples of continuous data would be 'height' or 'weight'. A bar chart is very useful if you are trying to record certain information whether it is continuous or not continuous data.

Example

The following table lists the number of seats allocated to each party group in European elections in 1999 and 2004. The results of 1999 have been multiplied by 1.16933, to compensate for the change in number of seats between those years. Sometimes it can be horizontal.
This bar chart shows both the results of 2004, and those of 1999: