This area chart compares Android and iOS user numbers over time, using green and gray filled regions to show yearly trends from 2009 to 2023. The visualization is rendered as an SVG using d3 v6, leveraging the `area` generator with `curveBasis` for smoothed paths and `scaleTime`/`scaleLinear` for axes. Data is loaded via `csv` from the author's GitHub repository, with a custom legend and axis labels. The chart employs `axisBottom`, `axisLeft`, and explicit margin calculations to position elements within a 960×500 viewport.