Drone Dictionary
A collection of abbreviations, brand names, definitions and a bunch of things that might be very confusing but will all be explained by the end of this.
Radio Control & Links
ELRS (ExpressLRS)
An open-source radio control system (hardware + firmware) that defines how control signals travel over the air between transmitter and receiver. Known for ultra-low latency and long range.
Crossfire (TBS Crossfire)
A proprietary long-range radio control system from Team BlackSheep, consisting of transmitter modules and receivers. Competes with ELRS in the same role.
CRSF (Crossfire Serial Protocol)
A digital serial communication protocol used between the receiver and the flight controller. Originated with TBS Crossfire but also used by ELRS. Provides fast RC signal transfer and telemetry support.
RSky, FlySky, Radiomaster, Jumper
Brand names for radio transmitters and receivers commonly used in FPV drones.
TX / RX
Transmitter (hand controller) and Receiver (on the drone).
VTX (Video Transmitter)
Sends video feed from the drone to the pilot’s goggles or ground station. Measured in mW power (25mW, 200mW, 1W, etc.).
VRX (Video Receiver)
On the ground; receives the FPV video feed.
Goggles
FPV headsets like DJI Goggles 2, FatShark, Skyzone.
Flight Control & Software
FC (Flight Controller)
The “brain” of the drone. Reads sensors (gyro, accelerometer, barometer, GPS, etc.) and outputs signals to control motors.
ESC (Electronic Speed Controller)
Converts flight controller signals into controlled power for the motors. Usually one per motor, but modern boards often use 4-in-1 ESCs.
BLDC (Brushless DC Motor)
Standard drone motors. Efficient, reliable, and high power-to-weight ratio.
Firmware
Software running on the FC (e.g., Betaflight, iNav, ArduPilot, PX4).
Mavlink
Open-source communication protocol used by flight controllers (ArduPilot, PX4) to exchange telemetry, navigation, and control data with ground stations.
QGroundControl (QGC)
A popular Ground Control Station (GCS) software for configuring and monitoring MAVLink-based drones. Alternative to Mission Planner (ArduPilot).
INAV
Firmware optimized for GPS navigation and stable flight (good for fixed-wings).
Betaflight
Firmware optimized for racing drones, freestyle FPV, and acrobatics.
PX4 / ArduPilot
More advanced open-source autopilot stacks used in research, mapping, delivery drones, and autonomous systems.
Navigation & Sensors
GPS
Provides positioning for navigation, return-to-home (RTH), and autonomous missions.
Compass / Magnetometer
Used for heading orientation. Usually built into GPS modules.
IMU (Inertial Measurement Unit)
Includes gyroscope and accelerometer. Core to stabilization.
Barometer
Measures altitude via air pressure. More precise than GPS for vertical positioning.
Optical Flow Sensor
Measures ground movement visually, used for indoor or GPS-denied navigation.
LIDAR / Radar / Ultrasonic
Used for obstacle avoidance or altitude hold.
Power & Batteries
LiPo (Lithium Polymer)
The most common drone battery type. Provides high current, but volatile if mishandled.
Li-ion
More energy-dense, longer endurance, but lower discharge rate (less burst power).
S (Cell Count)
4S (14.8V), 6S (22.2V). Higher S = more power and speed.
mAh (milliamp-hour)
Battery capacity. Higher means longer flight time.
C-rating
Discharge rate. Higher C = can deliver more current.
XT30, XT60, XT90
Common battery connectors.
Flight Modes & Functions
Acro Mode
Manual control, no stabilization. Used in racing/freestyle.
Li-ion
More energy-dense, longer endurance, but lower discharge rate (less burst power).
Angle Mode / Horizon Mode
Stabilized flight with self-leveling.
Return-to-Home (RTH)
Drone autonomously returns to takeoff point using GPS.
Loiter / Position Hold
Drone maintains position using GPS.
Failsafe
Safety protocol when signal is lost (hover, land, RTH).
Drone Types
Multirotor (Quadcopter, Hexacopter, Octocopter)
Most common for FPV and commercial drones.
Fixed-Wing
Longer endurance, good for mapping, BVLOS, and military-style ops.
VTOL (Vertical Take-Off and Landing)
Hybrid between multirotor and fixed-wing.
Cinewhoop
Small, ducted FPV drone for cinematic shots.
FPV Racer
High-speed, acrobatic drones for racing.
Ground Station & Ecosystem
Mission Planner
Ground control software for ArduPilot.
QGroundControl
Ground control software for PX4 and MAVLink.
DJI Ecosystem
Includes DJI FPV, O3/O4 Air Units, Goggles, and their proprietary controllers. DJI dominates consumer/professional market.
OpenTX / EdgeTX
Open-source firmware for transmitters (e.g., Radiomaster TX16S).
Telemetry
Data sent back to the ground station — battery, GPS position, speed, etc.