What is a Kernel? Simply explained

A Kernel is used in the computer everyday constantly and is constantly working for you. It is the intention that you notice him. He is basically the interface from the Software with a graphical interface that you use, and the system hardware.

• The Kernel is a Central module of an operating system. He is also sometimes referred to as a "Nucleus".
• He has a number of layers (Layer). The lowest layer is the interface to the system hardware, such as Network controllers or PCI-Express Controller.
• The next layer is the memory management, each process memory is assigned to them. Their application software includes a variety of such processes.
• The layer "process management" takes the time-Management and allows all the processes on your Computer seem to be running in parallel. The Kernel controls all requests from programs that fits you, one after the other and in case of problems, break.
• The top layer is the file system. It has processes areas on the HDD, so the hard driveand the memory to.
• The Kernel regulates the whole of the way from system hardware to application software, which nowadays, in turn, usually via a Graphical User Interface (GUI) from the User is serviced.
• Only the User area is not part of the kernel but is referred to as a "Shell", "Ring", or "Userland".
• A computer program sends system calls, called "System Calls", to the Kernel. Then makes the actual request in the machine language of the CPU. The Kernel knows the complete instruction set of the CPU, so all the machine commands that you can perform.
• These system calls are triggered, for example, if you import files on your Computer, or write. Also in the Background of this simple task happens all the time.
• In the case of multi-usersystems, monitors the Kernel, the access rights to files and hardware components.
• The Task Manager lists all processes that are managed by the Kernel. You finish a process in the Task Manager of the Kernel, this process to abort and to give the allocated memory back free.
• Since the Kernel is permanently needed, then it will be loaded as first after the Start in the memory. Usually this happens in a protected area that prevents it from being changed or deleted.
• Windows uses the NT Kernel, on the number of subsystems put. Apple uses the XNU Kernel. Linux systems such as Ubuntu and Android devices use the Linux Kernel.
• The Kernel is not the core of the processor, but the operating system's core or kernel.
• Multi-Kernel operating systems can use the different cores of a multi core processor, such as a network of independent CPUs.
• In the case of a Kernel is also not an API or a Framework, such as the NET Framework.

In the next practical tip we will show you how to make Linux find out which Kernel you have. In many other practical tips we will explain terms from the computer language, from the Software, such as VPN connection, BIOS and UEFI , or Firmware, to Hardware concepts, such as BUS, SSD , and motherboard.