This line chart visualizes the daily closing price of the S&P 500 index over time, using a temporal x-axis and quantitative y-axis. The visualization is built with Vega-Lite, whose specification defines the data URL, a simple line mark, and the field mappings. The chart is embedded into an HTML page via vega-embed, which loads both Vega and Vega-Lite from CDN. The underlying data is fetched directly from a hosted CSV file containing date and price columns.