This bar chart displays country populations with a mouseover effect that highlights the bar in red with a blue stroke and displays a text label showing the country name and formatted population (e.g., "China has Population of 1.42B"). The visualization uses D3 v6 APIs including `scaleBand`, `scaleLinear`, `axisLeft`, `axisBottom`, and `select` for interactivity. Data loads from a CSV via `d3.csv`, with populations multiplied by 1000, and renders as SVG rectangles sized from the scales.