This example presents a D3.js bubble chart that visualizes the relationship between GDP, population, and life expectancy for a dataset of nine countries. Each bubble’s position on the x-axis corresponds to GDP, its y-axis position to population, and its radius to life expectancy, with country labels placed at the bubble centers. The chart is rendered as an SVG with axes formatted using abbreviated number notation. The code loads data from a CSV file, converts string values to numbers, and builds the visualization using `d3.scaleLinear` for x/y/radius scales, `d3.axisBottom` and `d3.axisLeft` for the axes, and mouseover events that add a stroke to highlight a bubble.