From Halopedia, the Halo wiki
Freighter is a classification for interstellar vessels. These ships are neither armed nor well-protected, consisting almost entirely of cargo bay space for their transported goods. Many freighters are operated entirely by navigation computers and managed by planetary AIs, however some are still crewed by humans.
Many freighters are maintained by the Unified Earth Government, mostly to move supplies, food, and equipment to and from fringe worlds in the Outer Colonies. Most of these are maintained by the UNSC Department of Commercial Shipping, whose commercial fleet consists of hundreds of light freighters. Some private companies and individuals also maintain their own freighters. Some freighters were also used by militant Insurrectionist factions, such as the Eridanus rebels to supply their hidden base. Freighters operated by the UNSC have the hull classification symbol of DDA. Larger freighters are sometimes also converted into prison ships, used to transport convicts and goods to and from penal colonies.
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