This example presents a pie chart built with D3.js (v7) that visualizes categorical data by grouping rows from a CSV file by the "make" column. The chart uses `d3.pie` and `d3.arc` to generate the slices, with a color scale from `d3.scaleOrdinal` and `d3.schemeCategory10` to differentiate categories. A legend, constructed with SVG `rect` and `text` elements, maps each color to its category label. The SVG is rendered at 600x600 pixels, and the data is fetched from a remote URL via `d3.csv`.