> For the complete documentation index, see [llms.txt](https://docs.cb21829.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cb21829.org/ftc-java-beginner-guide/how-the-ftc-software-system-works.md).

# How the FTC software system works

Before touching code, understand the pieces:

* **Robot Controller (RC):** The brain. On modern robots this is the **REV Control Hub**. Your code runs here.
* **Driver Station (DS):** An Android phone, or the REV Driver Hub, that connects to the gamepads and talks wirelessly to the Robot Controller.
* **Control Hub / Expansion Hub:** These are where you physically plug in motors, servos, and sensors.
* **The FTC SDK:** A large Android project called `FtcRobotController`. Add your code to **`TeamCode`**. Never edit `FtcRobotController` directly.

An **OpMode** is a single program the robot can run. You write a class, tag it with an annotation, and it appears on the Driver Station.

There are two main types:

* **TeleOp** — driver-controlled. Reads gamepads.
* **Autonomous** — runs on its own for the first \~30 seconds.

The core loop of robot programming is simple:

**Read inputs → decide what to do → write outputs → repeat.**


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.cb21829.org/ftc-java-beginner-guide/how-the-ftc-software-system-works.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.