Two reusable D3 v5 legend components render categorical and quantitative scales side by side in SVG. A color legend uses `scaleOrdinal` to map fruit names to colored circles, while a size legend uses `scaleSqrt` with `ticks` to display varying radii for a numeric domain. Both components handle enter, update, and exit selections via `selection.data`, `merge`, and exit removal, positioning circles and labels with spacing and text offsets.