Cargo ships are small to mid-size civilian ships that specialize in transporting cargo. They are identical to freighter-class ships in function, but are much smaller and usually less well-armed. Cargo ships devote a large portion of their interior to a cargo hold, and usually have above-average engine power so that carrying a lot of cargo doesn't slow them down too much. They usually only require two or three crew members. Cargo ships usually only have one or two light weapons for defense, so they are often accompanied by fighter escorts to fend off against pirate attacks.