WinDirStat is a free and open-source disk usage analyzer for Microsoft Windows that helps users visualize and manage their disk space. Upon scanning a selected drive or directory, it presents the data in three views: a directory list, a file type list, and a treemap. The treemap displays each file as a colored rectangle, with the area proportional to the file’s size, making it easy to identify large files and directories. Users can interact with the interface to delete or manage files directly from the graphical display.