A pie chart visualizes categorical data by partitioning a circle into colored slices, with each slice sized proportionally to the value of its corresponding data point. The chart renders as an SVG using D3.js v7, employing `d3.pie` to compute the arc angles and `d3.arc` to draw the paths. A legend positioned to the right maps each slice’s color—assigned via `d3.scaleOrdinal` with `d3.schemeCategory10`—to its brand label. The data is loaded asynchronously from a remote CSV file, parsed for the `price` column as slice values.