A multi-line chart compares actual versus expected population figures for India, the USA, and China from 2015 to 2030. The visualization uses D3 v6 with SVG rendering within a React framework, with each country's actual and projected data drawn as distinct colored lines using `d3.line` and `d3.scaleTime`/`d3.scaleLinear` for axes. The code includes a tooltip and styles lines with the `.line` class. Data comes from a static CSV file containing yearly population values.