This bar chart displays the sum of a numeric column aggregated by a categorical column from a CSV file, automatically detecting the appropriate columns and sorting categories in descending order. Built with D3 v7, the visualization uses `d3.csv` to load data, `d3.scaleBand` and `d3.scaleLinear` for axes, and `d3.rollup` with `d3.sum` for aggregation. Bars are rendered as SVG rectangles with tooltips showing category and value, while grid lines and axis labels aid readability.