What is a Drone ?

A drone, formally known as an Unmanned Aerial Vehicle (UAV), is an aircraft that operates without a human pilot on board. These systems are part of an Unmanned Aircraft System (UAS), which includes the UAV, a ground-based controller, and a system of communications between the two.

• Autonomy: Drones can be controlled remotely by a human operator or fly autonomously using onboard computers, sensors, and GPS.
• Applications: They are used extensively in military (surveillance and tactical strikes), agriculture (crop monitoring), logistics (delivery), and disaster management.

Options A, B, and D are incorrect because they describe missile launchers, software threats, and maritime rescue equipment, respectively, which do not define a drone.