Drones are either
male bees or
robots.
In the latter case, they are characterized by high mobility, low individual intelligence, and power by plurality.
The novel The Two Faces of Tomorrow deals with the capabilities of drones and learning programs in some detail. To put it simply, drones rock my world.
In the novel, drones are small, individually stupid robots controlled by a master intelligence. Generally, a single drone is custom designed for a single task. They travel in groups, and are quite efficient at building, repairing, trouble shooting, and more.
They are a science fiction archetypical technology.