A horizontal bar chart displays city areas with custom-formatted axis labels, converting abbreviations like "G" to "B" for billions. The chart uses d3.csv to load data, d3.scaleLinear for the x-axis, d3.scaleBand for categorical y-values, and d3.axisBottom with a custom tick format function. SVG rectangles render the bars, with hover effects via CSS. The visualization includes a centered title and axis legend, with gridlines generated through tick sizing.