This bar chart displays population by country for 2015, with countries sorted in descending order along the x-axis and population values on the y-axis. The visualization is built using the Vega-Lite API, which composes a markBar specification with fieldN and fieldQ encodings, and renders via Vega’s SVG renderer. Data is loaded asynchronously from a CSV file using d3.csv, while a custom config adjusts axis styles and tooltip font sizes. The chart dynamically fits its width and height to the window viewport.