The Royal Air Force (RAF) operates several stations throughout the United Kingdom and overseas. This includes front-line and training air bases, support, administrative and training stations with no flying activity, unmanned airfields used for training, intelligence gathering stations and an early warning radar network. The list also includes RAF stations operated by the United States Visiting Forces, former RAF stations now operated by defence contractor QinetiQ on behalf the Ministry of Defence (MOD) and air weapons ranges operated by the MOD.