This bubble chart compares GDP per capita with life expectancy for countries worldwide, where each circle’s size reflects population and its color denotes continent. Hovering over a bubble reveals a tooltip with the country name, while focusing on a continent dims all other bubbles to highlight that group. The visualization uses d3.v4 with SVG rendering, d3-scale-chromatic for color schemes, and interactive CSS transitions for hover effects. Data is loaded from a remote CSV file, and scales are defined using d3.scaleLinear and d3.scaleSqrt.