This book explores Linux from the kernel’s perspective. It’s aimed at informed Linux enthusiasts—those who already know their way around Linux but are curious about how its internals fit together under the control of the kernel. The Linux kernel is highly efficient and deliberately hidden from the casual user, making it easy to overlook. This book is for readers who want to understand what’s happening “under the hood” and who’d like to dabble in kernel programming without necessarily becoming kernel developers. We deliberately skip low-level implementation details—such as device drivers—that don't directly support understanding core principles. Our approach combines hands-on command-line exploration, examination of relevant kernel source code, and kernel programming through loadable kernel modules. Specially designed Kernel Exercises help readers engage with internal kernel structures. These exercises involve writing and inserting kernel modules into a running system and then observing their behaviour. Anyone with basic programming skills and access to a working Linux system should be able to follow the examples and complete the exercises.