Overview of Part 101 regulations

Part 101 refers to the set of FAA regulations Shorthand for the portion of the United States Code of Federal Regulations (14 USC Part 101, Section 336) that regulates moored ballons, kites, amateur rockets, unmanned free ballons, and certain model aircraft, including some types of sUAS aircraft (drones) that may also be regulated under Part 107. A remote pilot who is certified to operate a sUAS under Part 107 has the option of operating that aircraft under Part 101. If the pilot of a sUAS aircraft is not certified as a remote pilot in command, that drone must be operated according to Part 101 regulations:

For sUAS aircraft, Part 101 regulations are similar to Part 107 regulations, with the following key exceptions:

No commercial operations: The sUAS aircraft can only be flown strictly for hobby or recreational use.
Maximum altitude: The UAV must fly no higher than 400 feet above ground level, with not exceptions for flying above structures that are higher than 400 feet.
Additional notification requirements: The UAV can fly without informing any airport operator or FAA ATC facility within five statute miles of the proposed flight activity. This responsibility extends to heliports that may or may not have active flight operations.
Following community based standards: These are the standards are based on guidelines from the Academy of Model Aeronautics (AMA), specifically the AMA National Model Aircraft Safety Code.

Registration requirements of sUAS aircraft
Currently, sUAS aircraft (drones) that weigh over 0.55 pounds (250 gm) are required to be registered with the FAA. If registration is desired or required, the person registering the aircraft must be at least 13 years old, and only one registration is required for all the drone aircraft owned by that registrant.

Other drone resources

Overview of Part 101 regulations
http://airsafe.com/issues/drones/part101.htm -- Revised 8 January 2018