A stacked bar chart displays the percentage of five rating levels across different movie genres, with hover tooltips revealing exact percentages. The visualization uses d3.stack() to compute stacked series and d3.scaleBand() for the categorical y-axis. SVG elements render the chart, while a tooltip div shows values on mouseover, with d3.format() controlling decimal precision. Data is loaded from irisdata.csv, though the dataset appears mislabeled as iris species rather than movie genres.