This scatter plot visualizes world population data for 2025, comparing each country’s population against its median age. Using D3.js v7, the code loads a CSV file, parses numeric values, and renders circles scaled with `d3.scaleLinear` for both axes. The SVG visualization includes axis labels, hover effects that change circle color, and tooltips via appended `title` elements. Data comes from a GitHub-hosted CSV source, and rendering uses standard D3 SVG primitives with margins and transitions.