This example demonstrates two reusable legend components rendered with SVG: a color legend mapping fruit categories to distinct hues, and a size legend visualizing a square-root scale from zero to ten with five labeled ticks. The color legend uses `scaleOrdinal`, while the size legend relies on `scaleSqrt` and `ticks()` to generate values. Both components are built with D3 v5’s `selection.enter` and `merge` pattern, applying circle radii, fill colors, and text offsets through `attr` and `text` operations. A video tutorial accompanies the code, showing interactive creation in the browser.