The 1st generally used drone appeared in 1935 as an entire-size retooling in the de Havilland DH82B "Queen Bee" biplane. It was fitted with a radio and servomechanism-operated controls in the back seat. If you're not positive of the main difference, have a look at our 'What are FPV drones?' https://socialexpresions.com/story2948105/not-known-details-about-category-2-drones