This bar chart compares smartphone models by units sold in millions, using a vertical bar encoding to show each model’s total sales. The visualization is built with React 16.9 and D3 v5, where a `d3.scaleBand` positions the categorical model labels on the x-axis and a `d3.scaleLinear` maps the numeric sales values to bar heights. Data is loaded as CSV via `d3.csv`, and the SVG bars are rendered with rotated x-axis tick labels to accommodate the long model names.