This example visualizes the Iris dataset as a scatter plot of sepal length against petal length, with each species distinguished by a distinct symbol shape and a legend labeling the species. The visualization loads the CSV data via fetch and d3.csvParse, then renders the plot using D3.js v7, constructing linear scales, ordinal shape encoding, and axes. The chart relies on reusable D3 modules for scatter plot rendering, axes, and a custom shape legend, with symbols generated via the d3.symbol and symbolsFill API.