A stacked bar chart breaks down 2018 sales for Consumer, Corporate, and Home Office segments, with each bar segmented by product sub-category and tooltips revealing exact item counts. The visualization uses D3.js libraries including `d3.layout.stack` for the stacked layout, `d3.svg.axis` for axes, and `d3.legend.color` for the interactive legend that highlights sub-category layers on hover. Animation is achieved through D3's SVG rendering, and the data comes from the provided CSV file.