This example demonstrates two legend types for visualizing data: a color legend and a size legend created side by side in an SVG. The color legend maps categorical fruit names (apple, lemon, lime, orange) to distinct colors using a d3.scaleOrdinal, while the size legend uses a range of numeric values to create circles of varying radii. Both legends are rendered through d3 data joins, where each group contains a circle and a text label positioned with transform attributes and spacing constants. The visualization uses d3.v5 and employs the colorLegend and sizeLegend custom functions to generate the reusable legend components.