> For the complete documentation index, see [llms.txt](https://huang-jason.gitbook.io/ros/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://huang-jason.gitbook.io/ros/master.md).

# Introduction

## GAZEBO

simulate 1+ robots in environments filled with static and dynamic objects, lighting, and programmable interactions.

**gzserver** = parsing the description files => simulates the complete scene

**gzclient** = connects to the gzserver & renders the simulation scene along with useful interactive tools.

```
$ gazebo
```

## Unified Robot Description Format (URDF)= XML format

1. define a robot model,
2. kinodynamic properties,
3. visual elements / sensors

CAN: describe a robot with rigid links connected by joints in a chain or tree-like structure.

CANT: flexible links or parallel linkage.

1 URDF = N Xacro (XML Macros)

## RViz = ROS Visualizer. (a ROS package)

RViz shows all 3 core aspects of a robot: Perception, Decision Making, and Actuation.