Carrot and radish are both fleshy taproots, but carrot has well-developed secondary phloem, while radish has well-developed secondary xylem. See the figure below for cross sections from the outside in: pericarp, primary phloem destroyed by extrusion, secondary phloem, formative layer (easily peelable part), secondary xylem, and primary xylem.

Carrot

Radish