Treemap

A treemap is a type of visualization that hierarchically displays data. It has the structure of a tree (hence the name) with the data organized in nested rectangles (one inside the other). The size of the rectangle corresponds to the value of the category or subcategory. The rectangles are called [nodes and are of root or leaf type](https://www.ibm.com/docs/en/spss-statistics/version-missing?topic=types-treemap-charts). The root node is the first one (it does not arise from another one), while the leaf node detaches from another one and is the last in the hierarchy. That means that the root node (category) total is the sum of the leaf nodes (subcategories). So, this type of visualization makes it possible to compare between subcategories and between categories. Colors represent the classification between rectangles, which makes it easy to identify the categories.