Linux came from a Uinux family. Just like Windows and Mac OS X, Linux is a computer operating system. It is free and open-source.

Used by 91% of applications on the internet.
Allows multi-user & multi-tasking with powerful shell
Allow high security, and doesn't need any anti-virus software.

Linux principles
1. Everything is a file
2. Small,single-purpose programs
3. Ability to chain programs together to perform complex tasks.
4. Configuration data stored in text.

Linux Architecture

1. Utilities/Applications

These are the applications and software that are running on the screen. These can be Browsers, Video Games, etc. These do not have direct access to the hardware for security concerns and requests to access hardware devices through system calls.

2. Shell

The shell is an interface for users to communicate with the kernel.Shell is a program that is used in UNIX-like systems to implement various instructions. It gives a computer user access to the Unix/GNU Linux system, allowing the user to perform various commands or utilities/tools with some input data. When the shell finishes executing a program it displays the result to the user on the standard output device, the screen.

As a result, it is known as the "command interpreter." The default shell in Linux is "Bash"

3. Kernel

The kernel is the fundamental part of the OS. It directly interacts with system hardware and manages resources.

example: If the OS is a restaurant, the kernel is the head chef. It oversees all the kitchen activities, ensuring all orders are cooked and ready on time.

• The following kernel varieties are mentioned:
  Monolithic Kernel
  Micro kernels
  Exo kernels
  Hybrid kernels

4.Hardware Layer

This is the actual physical layer of computers the various components like the CPU, memory, RAM, ROM, GPU, MotherBoard and hard drives.

Basic Commands of Linux

1. pwd : it shows the present working directory

2. ls : it shows available files & directory list in the present working directory

3. uname : it shows the name of the kernel(OS)

4. uname -r : it shows the version of the kernel

5. cd : it use to change the directory

6. clear : it use for clear screen

7. whoami : it shows currently login user name

8. history : it shows list of perviously used commands

9. date : it shows time and date

10. mkdir : to create directory

11. cp : is used to copy & paste file or directory

    Happy Learning!!

    Thanks For Reading! :)