A scatter plot visualizes the Iris dataset, mapping sepal length to the x-axis and petal length to the y-axis while encoding species with different SVG shapes (circles, crosses, diamonds) via a legend. Data is loaded asynchronously from a CSV and parsed with `d3.csvParse`. The code uses D3 v7 scales (`scaleLinear`, `scaleOrdinal`), axes, and a custom legend module built with `d3.symbol` and join patterns to render marks.