This book has been written with the objective of helping the beginners of Linux Operating System. The book categorizes the Linux commands into various categories in the form of questions. The answers are also given in the answers section. The questions and answers covers the basics of the Linux operating system. All the commands in the book are tested in Debian based Linux distributions.The book covers commands related to Package Management, Versions, System, Directory/File related operations, Search and Path functions, History, File name expansion, using Quotes, Job and Process operations, Archiving and Compressing, Cron, Syslog, User and Password Management, Runlevel, File system management, Service management and Permission related commands. The book is completely compiled using LaTeX. The advanced commands with more options will be covered in the future editions of this book. I wish all the readers for a successful career using Linux based Software development.