This line chart shows the annual number of Facebook users from 2008 to 2017. The visualization uses D3 v5 to load CSV data from a GitHub gist. The code employs `d3.scaleTime` for the x-axis and `d3.scaleLinear` for the y-axis, with `d3.axisBottom` and `d3.axisLeft` for tick marks. A `d3.line` generator creates the path, which is rendered as an SVG element with a custom stroke style.