A POW means the "prisoner of war" that was held captive by enemy forces for interrogation efforts about a prisoner's life of time being with his fellow members, like the 76th Mechanized Division of GDI for a member from the Brotherhood of Nod to reveal the entire information. After efforts of interrogation, the POW is sent to a POW camp to join other prisoners or if the talks fail, the prisoner gets tortured to reveal information for the enemy or die in consequences.
Most units and structures have POW camps. They are the American POW truck, Detention camp, Chinese POW truck, GLA POW truck, Prison, POW logic and a Chinese POW camp. Missions have notable rescues in the Command & Conquer universe such as Tanya's Tale, Hollywood and Vain, Stowaway, Circus of Treachery, The Shark and the Lure, Enemy of our Enemy, Pentagon (GDI mission), Stranded in Stuttgart, The Traceless Massacre, Time Shift, Dark Night, Sun Temple and much more.