Linux Kernel

The Linux kernel is the core of a Linux system. It lets applications use the processor, memory, storage, network, and other hardware while managing the work they share. A Linux distribution combines the kernel with system tools and applications to make a complete operating system. If you want to install Linux on a computer, start with a distribution; a kernel source download alone will not give you a usable desktop or server.

What the kernel handles

The kernel schedules processes and threads, manages virtual memory, and keeps one program's memory separate from another's. Features such as copy-on-write let processes share memory efficiently until they need to change it. These mechanisms are largely invisible in everyday use, but they affect how the whole system behaves under load.

Drivers give the system a way to work with hardware, from storage devices and network adapters to input devices. The kernel also supplies filesystem support and networking, including IPv4 and IPv6. It runs on a broad range of processor architectures and devices, although the features and drivers available on a particular machine depend on its kernel configuration and the surrounding distribution.

What changed in recent major versions

• Linux 4.x: The series brought in kernel livepatching, which lets administrators apply some critical fixes to a running kernel without an immediate reboot. It also continued the steady expansion of hardware and filesystem support.
• Linux 5.x: Linux 5.1 introduced io_uring, an interface for applications to submit and complete asynchronous I/O with less overhead. This mainly benefits software built to use it; it is not an automatic speed boost for every program.
• Linux 6.x: Linux 6.1 merged initial Rust support for kernel development. Linux 6.12 added sched_ext, which lets developers test BPF-defined scheduling policies while retaining a fallback to the normal scheduler. These are developer-facing capabilities, alongside the series' ongoing driver and architecture updates.
• Linux 7.x: By Linux 7.0, Rust support was no longer experimental and had become an established part of kernel development. Linux 7.1 added a modern in-kernel NTFS driver with full read and write support, useful when Linux needs to access Windows-formatted volumes. This is a new implementation, not Linux's first NTFS support. Linux 7.2 added groundwork for cache-aware task balancing and early Apple M3 platform support. Those changes target better use of shared CPU caches and broader hardware compatibility.

Which release should you use?

The upstream project has several release tracks. Mainline is where new features arrive. Stable releases receive fixes after a mainline release, while longterm branches receive selected fixes over a longer period.

Most people run a kernel supplied by their Linux distribution. Distributions may apply their own patches and maintain their kernels on a different schedule from kernel.org. Use your distribution's update and support channels when you need a routine security fix or hardware update. An upstream kernel is more relevant if you develop or test kernel code, need to investigate a specific change, or deliberately maintain a custom build.

Strengths and things to consider

Linux's open source code and configurable build make it adaptable to many kinds of systems. The kernel covers the essentials of process management, memory, devices, filesystems, and networking in one widely used foundation. It is distributed under the GNU GPL version 2, with licensing details documented by the project.

That flexibility also makes a manual kernel upgrade a technical task. Building one requires selecting configuration options, compiling the code and modules, and arranging for the system to boot it. A custom kernel can differ from the version your distribution tests and supports. Keep a working kernel available while experimenting.