Nodes communicate with each other by publishing messages to topics. A message is a simple data structure, comprising typed fields.
In the old tutorials we were using commands like
listener. Now as an example we are going to create a two new topics (talker_float and listener_float). This will publish float values.
The published messages are accesible from the network and are useful for communicate ROS 2 nodes between them. There are currently two programming languages in ROS 2 [
Python] and you should try both.