What is the Kernel?

The kernel is the center of a big operating system, the Linux kernel is like the heart of this huge system. "GNU/Linux" is the name if this operating system while the best way to call only the kernel is "Linux". The GNU/Linux is divided by two levels, user's space and kernel space. Inside the user's space is the GNU C Library and provides the bridge between the upper level which is the user space and the lower level, the kernel. The kernel can be divided by three different layers. The first one is the System Call Interface, the middle one is the kernel code, and the bottom is the Architecture-independent kernel code. The Linux operating system has become very stable and provides great memory use and CPU usage.