The Role of the Kernel

The kernel is the master executable of the system. It's the first thing that is executed from the boot blocks when you power on the system, and it constantly runs throughout the machine's uptime. Its job is to oversee all the processes running on the system, handle TCP/IP and other networking duties, manage access to all the devices on the system, and control memory usage—to name just a few of its tasks.

Every operating system has a kernel—from MS-DOS, to Windows, to the highest-end mainframe. Some systems take greater pains to hide it from the user than others do: In Windows, it's an executable in C:\WINDOWS\SYSTEM; in classic Mac OS, it's hidden from the filesystem entirely. In many UNIX systems, its traditional place ...

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