This D3.js pie chart visualizes social media usage percentages across ten countries, with each slice labeled by its corresponding value. The chart uses `d3.pie` to compute arc segments, `d3.arc` for generating the path geometry, and `d3.scaleOrdinal` to map categorical colors to each country. Data is loaded asynchronously from a CSV file using `d3.csv`. A legend on the right pairs each country with its percentage, and all text labels are formatted using `d3.format`. The SVG canvas is 960 by 500 pixels with a black background.