Frequently Asked Question

How is the Linux kernel different from GNU/Linux or a distribution?

The kernel is a single program, around 30 million lines of C. A distribution (Ubuntu, Fedora, Arch, Debian) bundles that kernel with the GNU C library, GNU coreutils, a shell, an init system, a package manager, and thousands of applications, then ships them as an installable image.

"GNU/Linux" is the older name that emphasises this division: the GNU project supplied the compiler (gcc), the libc, and most of the user-space tools that were used to bootstrap early Linux systems; Linus Torvalds supplied the kernel. Modern distributions often replace large parts of the GNU stack (musl instead of glibc, busybox instead of coreutils, systemd instead of sysvinit), so the "GNU" half is less universal than it was in 1992, but the layering, kernel below, user-space on top, is unchanged.