Barcode charts are used to show the value ranges of data divided into categories. When lines are used instead of dots to represent each data point—as in a dot plot—the visual begins to resemble a barcode, which is how this chart type got its name. While it is not possible to determine the exact count of values that are the same, barcode charts provide a very simple way to reveal the distribution range and density of the data. Although outliers are not explicitly visualized, special data points can easily be highlighted using color.