The simulator package Gazebo was introduced in Chapter 2, Creating Your First Two-Wheeled ROS Robot (in Simulation). If you run the examples there using the differential drive robot,
dd_robot, you should have a good understanding of Gazebo, including how to load models and worlds and manipulate the environment.
To run the simulator, you need to install the TurtleBot software, as described in the previous section. If you view the tutorials of TurtleBot Gazebo from the ROS wiki, make sure that you select Indigo since that should be your distribution of ROS.
To start the simulation, open a new terminal window and type the following command:
$ roslaunch turtlebot_gazebo turtlebot_world.launch
If all goes well, ...