This visualization is a scatter plot showing the relationship between patient age and heart rate, with data points shaped by gender. It uses D3 v7 to render symbols from the `symbolsFill` set, mapped via `scaleOrdinal`, and includes a custom legend for the shape encoding. The plot leverages `scaleLinear` for both axes and fetches healthcare data from a remote CSV. Key APIs include `d3.csvParse`, `d3.extent`, `d3.axisLeft`, `d3.axisBottom`, and the `d3.symbol` generator for drawing point shapes.