Terminology

You might have seen the terms ROS, ROS 1, ROS 2, and other kinds of variations (with or without a space), which can be confusing.

Let’s clear this up now:

• ROS 1 is (was) the first version of ROS
• ROS 2 is the second and newer version of ROS and will be the focus of this book

In this book, I will use the following convention:

• ROS: When talking about general ROS concepts, philosophy, and so on
• ROS 1: When talking specifically about the first version of ROS. However, this will be quite rare since the focus here is on ROS 2
• ROS 2: When talking about the second version of ROS

Note

I may sometimes write ROS or ROS 2 interchangeably since we won’t be focusing on ROS 1 here.

It’s not impossible that, in the future (when ROS 1 has completely disappeared), the name ROS 2 becomes ROS again. If you’ve heard about Angular, it started as AngularJS, after which they released Angular2, and then a few years later...