original_query: What is the significance of Yu-Gi-Oh! 5D's in relation to the Yu-Gi-Oh! franchise?
query: What is the significance of Yu-Gi-Oh! 5D's in relation to the Yu-Gi-Oh! franchise?
answer: Yu-Gi-Oh! 5D's is the second main spin-off of the Yu-Gi-Oh! franchise, following Yu-Gi-Oh! GX.  It introduced Synchro Monsters and a new dueling mechanic involving D-Wheels/Duel Runners to the Yu-Gi-Oh! Trading Card Game.