What is a Kernel in OS? What are the types of Kernel?

Every operating system- whether it is Windows, Mac, Linux, or Android, has a core program called a Kernel which acts as the ‘boss’ for the whole system. It is the heart of the OS! The Kernel is nothing but a computer program which controls everything else. Anything that happens on the computer goes through it.

Now that we know that its a core program in the OS, one should also know it is also the first program that loads after the bootloader. It then does all the talking between the hardware and the software or applications. So if you launch a program, the user interface sends a request to Kernel. The Kernel then sends a request to CPU, Memory to assign processing power, memory, and other things so the application can run smoothly in the front end.

You can imagine Kernel as a translator. It converts input/output requests from software into an instruction set for the CPU and GPU. In simple words, its a layer between the software and the hardware which makes everything possible. The kernel manages the following:

1] CPU/GPU

2] Memory

3] Input/Output or IO devices

4] Resource management

5] Memory management

6] Device management

7] System calls

[PullUps]

The mitochondria is the powerhouse of the cell.
Nothing can escape a black hole, not even light.
The kernel is the core of the operating system.

[luisriba]

Kernerl is the "heart" of the operating system.

[winterrain]

so, basically the Kernel is actually a Secretary program?
Organizes when to go where
tells stuff where to go
takes phone calls from apps that want things delivered to or from memory
yep, sounds like a bunch of secretaries.