This example displays two bar charts analyzing Airbnb listings in Boston. It shows the number of unique hosts per bed type and per cancellation policy, with each bar representing a category and the y-axis indicating host counts. The visualization uses D3.js v4, loading data from a CSV file with `d3.csv`, grouping entries via `d3.nest` and `rollup`, and counting unique host IDs with `d3.set`. Bar rectangles are appended to an SVG, with axes generated through `d3.axisBottom` and `d3.axisLeft`. The page also includes a separate React component drawing a panda face using D3 arc and ellipse shapes, though it is not integrated with the charts.