This example builds a scatter plot with a categorical legend, where data points are distinguished by shape. The visualization maps two quantitative variables to the x and y axes using `d3.scaleLinear` and assigns a different symbol to each category via `d3.scaleOrdinal` and `d3.symbol`. The chart includes axes with labels, drawn using `d3.axisLeft` and `d3.axisBottom`, and a custom legend that displays the shape mapping. The underlying data and its source are not specified in the provided code.