Rolls-Royce Holdings plc develops and delivers complex power and propulsion solutions for air, sea, and land in the United Kingdom and internationally. The company operates through four segments: Civil Aerospace, Defence, Power Systems, and New Markets. The Civil Aerospace segment develops, manufactures, markets, and sells aero engines for large commercial aircraft, regional jet, and business aviation markets, as well as provides aftermarket services. The Defence segment is involved in the development, manufacture, marketing, and sale of military aero engines, naval engines, and submarine nuclear power plants, as well as offers aftermarket services.