This horizontal bar chart visualizes the top 30 countries by population in 2020. The D3.js v7 code loads CSV data from a GitHub Gist, converts the '2020' column to numerical values, sorts the data in descending order, and selects the first 30 entries. Using `d3.scaleLinear` for the x-axis and `d3.scaleBand` for the y-axis, it renders steelblue rectangles within an SVG, with hover states turning them orange. The visualization also includes a left y-axis, a bottom x-axis with compact tick labels, and text annotations showing each population value.