A military reserve force is a military organization composed of citizens of a country who combine a military role or career with a civilian career. Reserve forces are generally not considered part of a permanent standing body of armed forces, but are instead mobilized as necessary. They are also known as reserve components, or more specifically as reserve formations. Reserve forces are generally made up of volunteers who train part-time while maintaining full-time civilian jobs. They may be called upon to serve in times of national emergency or to provide additional manpower for the regular armed forces during times of war or other crises.