This UBUNTU LINUX OS E-Book is published to help students or new users understand the LINUX operating system. This e-book uses Ubuntu as a learning tool for new users who want to learn more about the Linux operating system. Ubuntu is a popular and versatile Linux open source operating system. It is very flexible and can be modified to meet the specific needs of its users. Throughout the presentation of this e-book, the authors use step-by-step examples in a 'hands-on' way in running command code using a 'virtual machine'. Linux command code is written through 'command prompt' or 'vi editor'. Hopefully everything shared in this e-book will benefit everyone.