Aerospace & Defense refers to the industries involved in the design, development, and production of aircraft, spacecraft, and defense systems. This sector includes companies that manufacture commercial airplanes, military jets, satellites, and various types of weapons. Key players in this field include major corporations like Boeing, Lockheed Martin, and Northrop Grumman. The aerospace part focuses on flight technology and space exploration, while the defense aspect emphasizes national security and military capabilities. Innovations in this sector often lead to advancements in technology, such as drones and missile systems, which play crucial roles in both civilian and military applications.