A stacked bar chart shows the changing composition of four product categories across five years, from 2006 to 2010. The visualization uses d3.v3 with SVG rendering, building layers via `d3.layout.stack()` and mapping time with `d3.time.format`. Bars are colored per category, with a legend and interactive tooltips that display each segment’s value on mouseover. The data is embedded as JavaScript objects, not loaded from a file.