Aircraft performance refers to how well an aircraft can operate under various conditions. It includes factors such as speed, altitude, range, and fuel efficiency. Performance is influenced by the aircraft's design, weight, and engine power, as well as environmental conditions like temperature and wind. Key performance metrics include takeoff distance, climb rate, and stall speed. These metrics help pilots and engineers understand how an aircraft will behave during different phases of flight. Proper assessment of aircraft performance is crucial for safe and efficient operations, ensuring that the aircraft can meet its intended mission requirements.