The book begins with an introduction to RHEL 9's features, architecture, and its role in the open-source ecosystem, including comparisons with Fedora and CentOS. It then delves into practical aspects of RHEL 9 setup, covering installation methods, cloud deployments on AWS, Azure, and GCP, and subscription management. The book further explores application deployment and management, including software repositories, the GNOME desktop environment, infrastructure services, virtualization, containerization with Podman, networking, file storage, and DevOps pipelines. Finally, it addresses critical security and monitoring aspects, detailing security hardening techniques, capacity planning, log analysis, system auditing and an introduction to AI/ML frameworks on RHEL 9.