Nodes and Topics - nstiurca/ros-turtlebot-tutorial GitHub Wiki

Two of the most useful abstractions in ROS are Nodes and Topics. Nodes are essentially ROS executables which coordinate the interaction between your code and the ROS ecosystem. A typical program in ROS in composed of a node which communicates to other ROS nodes via topics. Topics are uni-directional many-to-many message pipes.

Let's explore the nodes available in the Turtlebot simulation.

$ rosnode list
/bumper2pointcloud
/cmd_vel_mux
/depthimage_to_laserscan
/gazebo
/laserscan_nodelet_manager
/mobile_base_nodelet_manager
/robot_state_publisher
/rosout
/rviz_1441171290561068258