I am not able to understand the difference between a kernel and an operating system. I do not see any difference between them. Is the kernel an operating system?
11 Answers
A kernel is the part of the operating system that mediates access to system resources. It's responsible for enabling multiple applications to effectively share the hardware by controlling access to CPU, memory, disk I/O, and networking.
An operating system is the kernel plus applications that enable users to get something done (i.e compiler, text editor, window manager, etc).
The technical definition of an operating system is "a platform that consists of specific set of libraries and infrastructure for applications to be built upon and interact with each other". A kernel is an operating system in that sense.
The end-user definition is usually something around "a software package that provides a desktop, shortcuts to applications, a web browser and a media player". A kernel doesn't match that definition.
So for an end-user a Linux distribution (say Ubuntu) is an Operating System while for a programmer the Linux kernel itself is a perfectly valid OS depending on what you're trying to achieve. For instance embedded systems are mostly just kernel with very small number of specialized processes running on top of them. In that case the kernel itself becomes the OS itself.
I think you can draw the line at what the majority of the applications running on top of that OS do require. If most of them require only kernel, the kernel is the OS, if most of them require X Window System running, then your OS becomes X + kernel.
The kernel is part of the operating system, while not being the operating system itself. Rather than going into all of what a kernel does, I will defer to the wikipedia page: http://en.wikipedia.org/wiki/Kernel_%28computing%29. Great, thorough overview.
The Operating System is a generic name given to all of the elements (user interface, libraries, resources) which make up the system as a whole.
The kernel is "brain" of the operating system, which controls everything from access to the hard disk to memory management. Whenever you want to do anything, it goes though the kernel.
Simple Answer
The Kernel is the core piece of the operating system. It is not necessarily an operating system in and of itself.
Everything else is built around it.
Ellaborate Definition
In computing, the 'kernel' is the central component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources (the communication between hardware and software components). Usually as a basic component of an operating system, a kernel can provide the lowest-level abstraction layer for the resources (especially processors and I/O devices) that application software must control to perform its function. It typically makes these facilities available to application processes through inter-process communication mechanisms and system calls.
The kernel might be the operating system or it might be a part of the operating system. In Linux, the kernel is loaded and executed first. Then it starts up other bits of the OS (like init) to make the system useful.
This is especially true in a micro-kernel environment. The kernel has minimal functionality. Everything else, like file systems and TCP/IP, run as a user process.
Kernel resides in OS.Actually it is a memory space specially provided for handling the os functions.Some even say OS handles Resources of system and Kernel is one which is heart of os and maintain,manage i.e.keep track of os.
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