This interactive bar chart displays population data for countries within a selected world region. Clicking a region name—Africa, Asia, Europe, Americas, or Oceania—triggers a fetch request to the REST Countries API, which returns country data for that area. The visualization uses D3.js to generate horizontal bars whose heights encode each country’s population, with rotated text labels showing country names and exact population values. The SVG is dynamically cleared and redrawn for each new region selection, with a hotpink styling used for the static bar examples.