> For the complete documentation index, see [llms.txt](https://docs.geprc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.geprc.com/01-getting-started/fpv-basic-conecpts/3.-fpv-glossary.md). # 3. FPV Glossary Entering the FPV hobby feels like learning a new language. We have compiled the most common technical terms, acronyms, and slang used in the drone community to help you get started. {% stepper %} {% step %} ### Purchasing & Kits (Must Read Before Buying) This is the most confusing part for beginners. Choosing the wrong version means you won't be able to fly when you unbox it. | Term | Full Name | Meaning & Explanation | | ------------- | ----------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **RTF** | **Ready To Fly** |

Complete Kit. Includes the drone, radio controller, goggles, batteries, and charger. You can fly immediately after charging.
(GEPRC Example: TinyGO Kit)

| | **BNF** | **Bind And Fly** | **Drone Only (Pre-built).** Includes a fully assembled and tuned drone. **Does NOT include** radio or goggles. You need to provide your own radio and "Bind" it to the drone's receiver before flying. | | **PNP** | **Plug And Play** |

No Receiver Installed.
1. If you use DJI Remote Controller 2 or 3, buy this version to connect directly to the Air Unit.
2. If you use a specific receiver not listed (e.g., a specific Futaba), buy this and solder your own receiver.

| | **ARF** | **Almost Ready to Fly** | **DIY Kit.** Usually includes all parts but requires you to assemble, solder, and tune the drone yourself. | | {% endstep %} | | | {% step %} ### Hardware & Electronics (Specs Guide) | Term | Full Name | Meaning & Explanation | | ------------- | ------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **FC** | **Flight Controller** | The **"Brain"** of the drone. It contains sensors (gyro) and calculates the drone's attitude and flight stability. | | **ESC** | **Electronic Speed Controller** | The component that controls motor speed. Modern drones typically use a **4-in-1 ESC** (four ESCs integrated into one board). | | **Stack** | **Flight Stack** |

Refers to the FC and ESC mounted together in a stack structure.
(GEPRC Example: TAKER F722 Stack)

| | **AIO** | **All In One** |

A board where the FC and ESC are integrated into a single PCB. Common on Whoops and toothpicks to save weight.
(GEPRC Example: TAKER G4 AIO)

| | **VTX** | **Video Transmitter** | Transmits the video feed from the camera to your goggles. Divided into **Analog** and **Digital** (e.g., DJI O3 Air Unit). | | **BEC** | **Battery Elimination Circuit** | A voltage regulator on the FC/ESC. It converts high battery voltage (e.g., 25V) down to 5V or 10V to power the VTX and Camera. **Note:** When using DJI O3, ensure the BEC supports **10V output**. | | **Li-Po** | **Lithium Polymer** | The standard battery type for FPV. High power output but sensitive. **Never over-discharge** (below 3.5V per cell) or it will be permanently damaged. | | {% endstep %} | | | {% step %} ### Flight & Settings (Operations Guide) | Term | Meaning & Explanation | | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Bind** | The process of pairing your radio controller with the drone's receiver so they can communicate ("Handshake"). | | **FailSafe** |

A safety mechanism triggered when the drone loses radio signal.
1. Drop: Motors stop immediately (Default for Freestyle).
2. GPS Rescue: The drone attempts to fly back to the home point (For Long Range).

| | **OSD** | **On Screen Display.** The flight data text overlaid on your video feed inside the goggles (e.g., Battery Voltage, Timer, Artificial Horizon). | | **Acro Mode** | **Manual Mode / Air Mode.** The standard mode for FPV. The drone **does not auto-level** when you release the sticks. This allows for flips, rolls, and smooth cinematic lines. | | **Angle Mode** | **Self-Leveling Mode.** The drone automatically returns to a flat, level position when you release the sticks. Useful for beginners or emergencies. | | **Turtle Mode** | **Flip Over After Crash.** A feature that reverses two motors to flip the drone back over if it lands upside down. Saves you the walk of shame! | | **Jello** | **Jello Effect.** High-frequency vibrations in the video feed that look like wobbling jelly. Causes: Damaged props, loose screws, or bad PID tuning. | | **PID** | **Proportional-Integral-Derivative.** A control loop mechanism. Tuning PIDs changes how the drone feels and responds. *(GEPRC drones come pre-tuned, so beginners rarely need to touch this).* | | {% endstep %} | | | {% endstepper %} | | {% hint style="info" %} If you messed up your settings in Betaflight and the drone flies weirdly (or won't arm), don't panic! Go to the **"Support / Download Center"** on our official website (`geprc.com`), download the **Factory CLI (Command Line)** file for your specific model, and load it in Betaflight. This will restore the drone to its original factory state. {% endhint %}