A line chart displays Facebook's annual user counts from 2008 to 2017, with years on the x-axis and user numbers on the y-axis. The visualization uses D3 v5 with SVG rendering, employing `scaleTime` for the date axis, `scaleLinear` for the value axis, and a `line` generator to create the path. Data loads from a CSV hosted on GitHub Gist using the `csv` function, and the chart includes labeled axes, grid lines, and a title.