This example uses a parallel coordinate plot to show the relationships between four numerical measurements (sepal length, sepal width, petal length, and petal width) across three species of iris flowers. Grey background paths provide context, while colorful foreground paths, colored by species via `d3.scale.ordinal`, highlight individual data points. Users can drag the vertical axes to reorder the dimensions, with smooth transitions animated by `d3.transition`. The visualization is rendered with SVG, using `d3.svg.line` and `d3.svg.axis`, and loads its data from a remote CSV file.