Camp ships were Yuuzhan Vong ships used to house refugees after the Battle of Coruscant. Made of masses of hexagonal chambers of various sizes glued together, they lacked life support systems, engines, or any kind of supplies. The Yuuzhan Vong filled them with millions of Coruscanti refugees and sent them to inhabited systems, which faced two options: either help feed the refugees, or let them die aboard the ships. With most systems' resources already strained by the necessities of the war, few had spare supplies, but none could neglect the needs of so many people.
Very few refugees were allowed to leave the camp ships, for in some worlds refugees planetside carried with them diseases, spies, saboteurs, collaborators, Peace Brigaders and other unpleasant surprises. As camp ships were huge, and no New Republic system had the resources to build cities to house so many people, the refugees were left there while the host systems did their best to supply them with food, water, light, and recycling systems. Even in the wealthiest systems life in camp ships was hard: the food was rationed to the point of starvation, and the atmosphere and water felt used and used again.
Some people thought that maybe some camp ships were sent to uninhabited systems, and some Jedi went to explore deep space with the Force. Nevertheless, the few Jedi in the galaxy were busy with the war, and no planetary or system wide governments mounted any searches.