This example uses Vega-Lite API within React and D3 to create a bar chart of population by country, colored by religion. The visualization loads CSV data from a GitHub gist and renders an interactive bar chart with tooltips showing population values. It uses `vl.markBar`, `vl.x().fieldN('country')`, `vl.y().fieldQ('population')`, and a color encoding for religion. The chart fits to the window size and applies custom axis styling from a config object, with a Vega Tooltip handler for interactivity.