While most of the disk usage analyzers use bar chart and pie graph to display the statistics, WinDirStat uses a treemap to display the data. You will see lots of colored rectangles within rectangles. A treemap is a visual representation of the node concept. The biggest rectangle represents the hard drive while the next biggest rectangle within represents the directories. In each of the directory rectangles, there are lot more smaller rectangles that represents the files inside that directory. The bigger the file size, the bigger is the rectangle. The rectangles are coded with color to represent various file formats, for example, blue stands for executable file, while red stands for image files. In WinDirStat, there are two panels – the top and bottom. The bottom panel shows the treemap while the top panel shows the file path. When you clicked on the rectangle, the top panel automatically navigate to (and highlight) the selected file. You can then decide if you want to delete the file on the top panel.