The knarr was the Viking ship type built mainly for carrying cargo. Compared with a warship, it was broader, deeper, and designed to transport goods, livestock, and sometimes passengers across open water.
Knarrs supported the movement of supplies between Scandinavia, the British Isles, Iceland, Greenland, and other North Atlantic settlements. Their sailing ability was especially important because many routes crossed rough seas far from shore.
A longship was optimized for speed, maneuverability, and coastal warfare, while a knarr sacrificed some of those qualities for capacity. “Drakkar” is a modern popular term rather than the standard name for every Viking warship, making knarr the precise answer here.