There are as many drones as there are uses. Drone types mainly fall into four categories: CP helicopters (Collective Pitch), multicopters, VTOL (Vertical Take-Off and Landing) and fixed-wing drones (aeroplanes).
The different types and fittings are suited to different purposes and may vary significantly. It is virtually impossible to assemble one single machine that would work in any situation or environment. A multicopter built for industrial measurement surveys is very different from a multicopter designed for photography or videography. Outwardly, they may appear very similar, and it is important to keep in mind that not all functions and features of an aircraft can be spotted from its appearance.