Practical UNIX

Important UNIX Concepts You Must Know First

The following sections cover the basic features of the UNIX operating system you need to understand.

The UNIX Kernel

In Figure 1.1, you can see the UNIX operating system represented as three concentric circles. The innermost circle is called the kernel, which refers to the nucleus or core of the operating system. The kernel is the most hidden part of the operating system. It contains code called drivers; these allow the system to control all the system hardware, the disk drives, the peripherals, and so on.

Figure 1.1. UNIX kernel, utilities, and shell.

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The next circle represents ...