All unmanned aircraft in the US over 0.55 lbs, regardless of for commercial or recreational use, MUST be registered with the FAA. You can register your drone HERE. Once you register your drone, you have to either "affix" it to your drone (aka - stick it on there somewhere) or it must be stored somewhere that is accessible WITHOUT a tool. Remember this for the exam!
Another topic that keeps coming up on the FAA exam has to do with registration of a foreign drone. The FAA's unmanned aircraft registration rules state that in order to register your drone in the United States, the drone must NOT be "registered under the laws of any foreign country." If you want to register a drone in the US that is currently registered in a foreign country, you must first de-register the drone in the foreign country and THEN register it in the US. Please remember this for the exam!
If you want to read more about the FAA's drone registration rules, you can go to the FAA website here.
The Remote Pilot in Command (RPIC) is the person who is ultimately responsible for the safe operation of the unmanned aircraft. They must hold a valid and current Remote Pilot certificate. It is required that one RPIC be designated before each flight. The RPIC has the final say for all flight operations, whether to fly or not depending on the condition of the weather, the unmanned aircraft itself, and the overall flight environment and circumstances.
Other individuals without a Remote Pilot certificate may also fly the unmanned aircraft for commercial purposes, but in these instances the person manipulating the controls must be supervised by the RPIC and the RPIC must be able to take back control at any moment.
The RPIC must also conduct a pre-flight inspection to ensure that the aircraft is suitable for safe operation.