Kernel

What is Kernel?

 - It is the heart of OS
 - An OS system provides many more services than a plain kernel.
 - Kernel prevents anyone from accessing the hardware directly.
 - Tools provided by the kernel are  used via system calls
 - System Programs and all other programs, run on "top of kernel", in what is called the user mode.
 - The difference between system and application programs is one of intent:
 
	
Important parts of the Kernel:

	- Process Management - creates processes, switching the active process on the processor
	- Memory Management - memory areas and swap space areas to processes and for buffer cache
	- Hardware device drivers
	- Filesystem drivers
	- Network Management
	- Various other bits and pieces
	
	
	- At the lowest level, kernel containts a hardware device driver for each kind of hardware it supports.