A line chart displays temperature measurements over a week in San Francisco, with time on the x-axis and temperature on the y-axis. The SVG visualization uses d3.scaleTime and d3.scaleLinear to map data, d3.line with curveBasis to generate the smoothed path, and d3.axisBottom and d3.axisLeft for labeled axes. Data is loaded via d3.csv from a remote dataset, with timestamps parsed as Date objects and temperatures converted to numbers.