What is Kernel in Operating System? Objectives and 5 Types of Kernal

What is Kernel in Operating System

In this article you are going to read about What is kernel in operating system, their objective and 5 types.

The kernel is the protected part of an operating system that runs in the kernel mode.

It is the first layer of operating system that was only the objects and operations provided by the hardware.

Kernel is the control module of of an operating system.

It means OS is nothing without Kernel. You can also say, this is the most important part of An Operating system.

When you give power to the computer, the first thing that loads boot-loader after that Kernel because they also have to manage their OS. They also stores memory until the shutdown of system.

It is important for the kernel to be as small as possible and then still providing all the important services required by the other parts of an OS and applications.

Objectives of Kernel in Operating System

  • Decide and Managing the incoming processes.
  • Control task management.
  • Control Memory Management
  • Control Disk Management
  • Control Process Management

Types of Kernel in Operating System

Monolithic, Micro, Hybrid, Nano, and Exo are the 5 different types of kernel are present. They all have unique features that make them different from others. Let’s take a look at some more details about their types.

Monolithic Kernel

This is OS architecture where the entire Operating System is operating in kernel space. It has more complex code than others. It has more dependencies between the system Components. UNIX and LINUX are some basic examples of Monolithic Kernel.


Through only system calls, it provides system scheduling, memory scheduling, and file management, as well as Performance, is very good.


Any service failure may cause whole system failure.


This is different from monolithic because this is micro, user and kernel services are executed into different spaces.

Using kernel space and user space reduces the kernel size and it directly affects the performance of OS in a good way by reducing the OS size.


  • It is very easy to add new services to this kernel version.
  • More stability than others.


There are lot of context switches in this version.

Hybrid Kernel

The combination of Monolithic and Micro makes Hybrid Kernel. They takes stability from micro and speed from monolithic, that makes him a good choice.


It has both speed as well as Stability.


Having all the features not good for this because it reduces the performance of hybrid.

Nano Kernel

According to his name, the whole code of this kernel is very small. The nano kernel means the process of working is nanosecond. 

It offers hardware abstractions without system Services. This is the same as microkernel but not used same as micro.


It can run within just 100 KB of memory.


They are small kernels relatively to others, they provide very basic OS services.


This is different from others in their design complexity, but they can follow end to end principle. It is also hard for application developers because they have to do more work than other versions looking at their complexity.


Fewer hardware abstractions


Very complex design is the disadvantage of this kernel.


There are 5 types of kernels they all have their own features and capabilities to operate an Operating system. Here is a simple article on what is kernel in operating system, functions, and their types.

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