What you need for this book
The requirement of this book is based on the use of CentOS 7, a community-supported distribution derived from sources freely provided to the public by Red Hat. As such, CentOS Linux is functionally compatible with RHEL (Red Hat Enterprise Linux), although some package names may have been changed in order to remove upstream vendor branding and artwork. CentOS Linux is available for free, at no cost, and free to redistribute.