For installation instructions see Section 8.3.
Linux (2.4.22):
ftp://ftp.kernel.org/pub/linux/kernel/
The Linux kernel is at the core of every Linux system. It's what makes Linux tick. When a computer is turned on and boots a Linux system, the very first piece of Linux software that gets loaded is the kernel. The kernel initializes the system's hardware components: serial ports, parallel ports, sound cards, network cards, IDE controllers, SCSI controllers and a lot more. In a nutshell the kernel makes the hardware available so that the software can run.
Installed files: the kernel and the kernel headers
The kernel is the engine of your GNU/Linux system. When switching on your box, the kernel is the first part of your operating system that gets loaded. It detects and initializes all the components of your computer's hardware, then makes these components available as a tree of files to the software, and turns a single CPU into a multi-tasking machine capable of running scores of programs seemingly at the same time.
The kernel headers define the interface to the services that the kernel provides. The headers in your system's include directory should always be the ones against which Glibc was compiled and should therefore not be replaced when upgrading the kernel.