The core of the Linux operating systems, created and maintained by Linus Torvalds
Linux kernel is the essential part of any Linux operating system. It is responsible for resource allocation, low-level hardware interfaces, security, simple communications, basic file system management, and more. Written from scratch by Linus Torvalds (with help from various developers), Linux is a clone of the UNIX operating system. It is geared towards POSIX and Single UNIX Specification compliances.
Features at a glance
Linux comes with powerful features, such as true multitasking, multistack networking, shared copy-on-write executables, shared libraries, demand loading, virtual memory, and proper memory management. Initially designed only for 386/486-based computers, now Linux supports a wide range of architectures, including 64-bit (IA64, AMD64), ARM, ARM64, DEC Alpha, MIPS, SUN Sparc, PowerPC, as well as Amiga and Atari machines.
The most essential component of a GNU/Linux operating system
The most essential component of a Linux-based operating system is the Linux kernel. Without it, the entire system (libraries, applications, etc.) is useless. When creating a Linux distribution, it is also very important to know how to correctly optimize the Linux kernel package, in order to make it support certain hardware components or recognize a specific device.
Distributed in multiple stable branches
One should not be confused by the many stable branches of the Linux kernel, as they are available for different purposes. For example, there are several LTS (Long Term Support) branches that can be used to deploy very stable Linux operating systems. These days, major Linux distribution developers provide users with optimized kernel packages for different purposes. However, advanced users can configure, compile and install their own kernels directly from the source packages at any point (all you need is a supported GCC compiler).
The heart of a Linux distribution
The Linux kernel is the heart of a Linux distribution. If you are a long time Linux user, you may have stumbled across upgrades to the default Linux kernel packages, which lead to better support for certain hardware components or peripherals.