In a vertical bar graph, we plot the various frequencies for different classes in the form of vertical bars. We also do this in a pareto chart, but in addition, we plot the cumulative frequencies (expressed in percentage) above the bars and join them by straight lines.

The below image shows an example of a pareto chart.

As we can see in the above image, the cumulative percentages have been plotted above the bar graphs and have been joined by straight lines. Therefore, a pareto chart has a line graph above the bar graph.

Moreover, in a pareto chart the categories/bars always represent some kind of factors for the occurrence of an event. As we can see in the above image, the bars represent the different causes for casting defects.

*To summarize, a pareto chart is different from a standard vertical bar graph in the following two ways:*

- The pareto chart includes a line graph showing cumulative frequencies (expressed in percentage) above the vertical bar graph.
- In a pareto chart the categories/bars always represent some kind of factors/causes for an event.