You're reading the documentation for an older, but still supported, version of ROS 2. For information on the latest version, please have a look at Jazzy.

Beginner: CLI tools

• Configuring environment
• Using turtlesim, ros2, and rqt
• Understanding nodes
• Understanding topics
• Understanding services
• Understanding parameters
• Understanding actions
• Using rqt_console to view logs
• Launching nodes
• Recording and playing back data