What is Linux?

Linux is an operating system, much like Windows or macOS, that manages the hardware resources of a computer and provides a platform for software applications to run. It was created by Linus Torvalds in 1991.Linux is open-source, meaning its code is freely available for everyone. Anyone can view, modify, and distribute the code, fostering collaboration and community-driven development. It is famous for being stable, secure, and adaptable. It works on various devices, like regular computers, big servers, and even small embedded systems.

Linux Architecture:

Linux follows a modular and layered architecture. Here's a simplified overview:

• Hardware layer:

  Hardware is like the toolbox of your computer. It includes everything you can touch(RAM/ HDD/ CPU etc.).

• Kernel :

  The Linux kernel is like the boss of a computer. It talks to all the parts inside, like memory, the brain (CPU), and devices. It helps them work together so your computer can do what you want.

• Shell:

  The shell is a command-line interface that allows users to interact with the system by typing commands.

  1. bash- Bourne-Again Shell

  2. bs- Bourne Shell

  3. csh- C Shell

  4. tcsh

  5. ksh- KornShell

• User Applications :

  There are typically three types of users:

  1. Superuser (Root):
     Root is like the computer boss with superpowers. It can do anything, even change important stuff. But, be careful using these superpowers to avoid breaking things accidentally. It's UID is zero (0).

  2. Regular Users:

     Regular users are like everyday guests on a computer. They can use it and change their stuff, but they can't mess with important computer parts without special permission from the boss (superuser).It's UID range is 500 - 60000.

  3. System Users:

     When you install the operating system or certain software, some users are automatically created. They're like invisible helpers with special tasks. They can't log in, and their UID numbers are between 1 and 499.