This book explains how to use Git from command line on Windows, Mac OS and Linux. The goal of this book is to get you up and running using Git from the command line as quickly as possible without overwhelming you with too much information. To make the learning process more intuitive and engaging, I use mental models, analogies and metaphors to help you understand and remember the concepts. I also use diagrams and illustrations. They help you visualize complex ideas and also serve as a bit of entertainment to keep you engaged. At the end of each chapter, you will find exercises that are crafted to reinforce the concepts you have just learned. These exercises are hands-on tasks that allow you to apply the new knowledge. By practicing what you learn, you understand the topics better and solidify the information in your memory. It is important to do the exercises. They will help you learn Git faster. Why Use the Command Line? Git has many applications with graphical user interfaces (GUI). Some of them are very good. So why use the command line? I believe using Git from the command line is the best way to learn it. It’s also the most flexible way to use it. You won’t be limited to a particular GUI application or an editor plugin. You will be able to use Git from a remote server, from a virtual machine or from a Docker container. So you’ll be a lot more powerful.