This bar chart displays population estimates for ten countries, using a horizontal layout with a linear x-scale and a band y-scale. A tooltip appears on mouseover, showing each country’s name and population, positioned dynamically near the cursor. The chart also includes formatted tick labels and dashed gridlines. Built with d3.v5, the visualization uses SVG rendering, d3.scaleLinear, d3.scaleBand, d3.axisBottom, and d3.axisLeft, with mouseover and mouseout event handlers to control tooltip opacity and positioning.