PPT on Linux Architecture.

1. UNIX System Architecture
By – Md. Noor & Sumit
Pandey

2. INTRODUCTION TO Unix Architecture

3. FOUR LAYERS OF UNIX ACHITECTURE
HARDWARE KERNELL​ SHELL​​ UTILITIES

4. K E R N E L
Kernel is the core component of Operating System where actual code and
functionality of OS lies.
It is responsible for scheduling running of user and other processes.
It is responsible for allocating memory.
It is responsible for managing the swapping between memory and disk.
It is responsible for moving data to and from the peripherals.

5. KERNEL MODE Vs USER mode
Kernel mode is used to perform lower level functionalities
& in user mode, the code has no access to hardware or lower level
resources like memory.
The kernel (which is the core of the OS and has complete control over
everything that occurs in the system) is trusted software.
User Mode, A non-privileged mode for user programs, that is,
for everything other than the kernel.

6. S H E L L
An interface for the user through which we can interact with the operating system.
A shell environment allows you to run commands, programs and shell scripts.
There are different types of shells, In UNIX there are two major types of shells -
(i) Bourne Shell - The default prompt is $ character.
(ii) C Shell - The default prompt is % character.

7. U T I L I T Y
Utility are the programs that perform various tasks.
For each user working with UNIX at any time, different shell programs are
running.
Thus at a particular point in time there may be several shells running in
memory but only one kernel.
As the users interacts with the kernel through the shell, different shells are
necessary.

8. ANY QUERIES ?

9. T H A N K Y O U !