In its early days, Linux development revolved largely around the central
operating-system kernel-the core, privileged executive that manages all
system resources and that interacts directly with the computer hardware.
We need much more than this kernel to produce a full operating system,
o£ course. It is useful to make the distinction between the Linux kernel and
a Linux system. The Linux kernel is an entirely original piece of software
developed from scratch by the Linux community. The as we
know it today, includes a multitude of components, some written from scratch,
others borrowed from other development projects, and still others created in
collaboration with other teams.