Chapter 2. ROS Architecture and Concepts

Once you have installed ROS, you certainly must be thinking, "OK, I have installed it, and now what?" In this chapter, you will learn the structure of ROS and the parts it is made up of. Furthermore, you will start to create nodes and packages and use ROS with examples using Turtlesim.

The ROS architecture has been designed and divided into three sections or levels of concepts:

The first level is the Filesystem level. In this level, a group of concepts are used to explain how ROS is internally formed, the folder structure, and the minimum number of files that it needs to work.

The second level is the Computation Graph level where communication between processes and systems happens. In this section, we will see all the concepts and systems that ROS has to set up systems, handle all the processes, communicate with more than a single computer, and so on.

The third level is the Community level where there are certain tools and concepts to share knowledge, algorithms, and code from any developer. This level is important because ROS can grow quickly with great support from the community.