And: "Use the Source, Luke!"
You can install "kernel-source" packages on your computer and browse the
actual implementation of everything at your leisure.
Be aware that Linux runs on more than twenty
hardware platforms ("/arch-itectures ...")
, and that over time it has evolved in many different ways and continues to do so. Some implementation details are very specific to the particular kernel version that you are using, and, to a lesser extent, the hardware capabilities of your particular system's microprocessor and motherboard. On the system-software side, a great deal depends on whether or not your system uses the systemd
system-management process. And so on and on and on.
Check the publishing-date and applicable kernel-version of any resource that you use.