How Linux Works

The Kernel

You now know what the Linux directory structure looks like. Before going on to devices and filesystems, you must learn some higher-level concepts about the kernel.

The kernel of an operating system is the very core of a running system. It's a very special program that manages all processes, device drivers, and I/O. When the system boots, the kernel runs first, initializing hardware and internal data structures. After the kernel completes this stage, it loads and starts the init program.

The kernel also has many functions once the system boots. Process and device management are the most important. The idea is that although computers with one CPU run only one program at a time, the kernel can keep several programs in memory at the same ...