Vikings used long, narrow longships built for speed and maneuverability in warfare, exploration, and travel. They had unique innovations like side rudders. Larger knarr and karve ships were used for longer Atlantic voyages to transport people, livestock, and goods, with knarr designed for longer trips and karve for shallower waters. Vikings had their own measurement units for distance, area, weight, money, and rates of exchange. Their everyday technology included fire-starting tools and animal bones used for knives, combs, and other tools.