This D3.js scatter plot visualizes the Iris dataset, mapping petal length and width for each specimen. Points are colored by species (setosa, versicolor, or virginica) using a categorical color scheme. The SVG rendering uses `d3.scaleLinear`, `d3.extent`, `d3.axisBottom`, and `d3.axisLeft` to construct the axes and plot, with data loaded asynchronously via `d3.csv`. Circle size is fixed, and the layout adapts to the browser window dimensions.