This example shows a word cloud visualization that displays frequency-weighted terms from JSON datasets, with buttons to toggle between family names and first names. The code uses D3 v3’s `d3.layout.cloud` plugin to arrange words in a spiral layout, scaling font size with `d3.scale.linear` based on each term’s count. Rendering occurs as SVG text elements styled with Impact font and a categorical color scale, while a setTimeout-driven animation progressively places words until the layout completes.