Basic Fundamentals Of Linux

1. Introduction of linux

Linux is a community of open-source Unix like operating systems that are based on the Linux Kernel. It was initially released by Linus Torvalds on September 17, 1991. It is a free and open-source operating system and the source code can be modified and distributed to anyone commercially or noncommercially under the GNU General Public License. In simple words linux is basically a open source operating system. Initially, Linux was created for personal computers and gradually it was used in other machines like servers, mainframe computers, supercomputers, etc. Nowadays, Linux is also used in embedded systems like routers, automation controls, televisions, digital video recorders, video game consoles, smartwatches, etc. The biggest success of Linux is Android(operating system) it is based on the Linux kernel that is running on smartphones and tablets. Due to android Linux has the largest installed base of all general-purpose operating systems. Linux is generally packaged in a Linux distribution. Linux is around us since the mid-90s. It can be used from wristwatches to supercomputers. It is everywhere in our phones, laptops, PCs, cars and even in refrigerators. It is very much famous among developers and normal computer users.

2. What is linux bash

The Linux Bash is also known as 'Bourne-again Shell.' It is a command language interpreter for the Linux based system. It is a replacement of Bourne shell (sh). It was developed under the GNU Project and written by Brian Fox. Nowadays, Bash is the default user shell of most of the Linux distributions.

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The Linux/Unix shell allows us to interact with the Linux system through the commands. It let us invoke an executable file to create a running process. Moreover, it also allows us to interact with the Linux file system. It is designed in such a way that we can perform all the Linux operations through Bash.

The Bash is a command language interpreter as well as a programming language. It supports variables, functions, and flow control, like other programming languages. It can also read and execute the commands from a file, which is called a shell script.

3. What is linux terminal

Linux OS, when we click to open the icon having the name “Terminal”, a window is opened, so in simple terms that rectangular frame or window is called terminal. With the invention of modern computers, we have this application named “Terminal”, which we can simply open with a click but during the 80s, it used to be known as “Terminal Emulators” which was not a software program but hardware, a normal Input-Output Device consisting of a keyboard and a monitor. Now the confusion arises well this is what a computer is!! But No, the purpose of a terminal is not to process information (like a typical computer) but to send commands to another system. The terminal is a program that provides the user with a simple command-line interface and performs the following 2 tasks:

Takes input from the user in the form of commands Displays output on the screen

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4. Structure of Linux karnel

Kernel: Kernel is the core of the Linux based operating system basically karnel is the heart of the operating system. It virtualizes the common hardware resources of the computer to provide each process with its virtual resources. Different types of the kernel are:
Monolithic Kernel
Hybrid kernels
Exo kernels
Micro kernels
System Library: This Is the special types of functions that are used to implement the functionality of the operating system.
Shell: It is an interface to the kernel which hides the complexity of the kernel’s functions from the users. It takes commands from the user and executes the kernel’s functions.
Hardware Layer: This layer consists all peripheral devices like RAM/ HDD/ CPU etc.
System Utility: It provides the functionalities of an operating system to the user.

5. Why linux use for security administration purpose

In case of windows or other operating system user can easily access all the storage files and information but in case of linux it is can's possible to access files or information without permission. Admin can easily restrict any file for example read permission , write permission & execute permission so that anyone can't access file without being a password. It provide high security to all the system in each level vulnerability.

6. What is linux distribution

There are on an average six hundred Linux distributors providing different features. Here, we'll discuss about some of the popular Linux distribution today. But Linux is different from them. Different parts of Linux are developed by different organizations.

Different parts include kernel, shell utilities, X server, system environment, graphical programs, etc. If you want you can access the codes of all these parts and assemble them yourself. But its not an easy task seeking a lot of time and all the parts has to be assembled correctly in order to work properly.

From here on distribution comes into the picture. They assemble all these parts for us and give us a compiled operating system of Linux to install and use.

Ubuntu:

It came into existence in 2004 by Canonical and quickly became popular. Canonical wants Ubuntu to be used as easy graphical Linux desktop without the use of command line. It is the most well known Linux distribution. Ubuntu is a next version of Debian and easy to use for newbies. It comes with a lots of pre-installed apps and easy to use repositories libraries.

Earlier, Ubuntu uses GNOME2 desktop environment but now it has developed its own unity desktop environment. It releases every six months and currently working to expand to run on tablets and smartphones.

Linux Mint:

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Mint is based on Ubuntu and uses its repository software so some packages are common in both.

Earlier it was an alternative of Ubuntu because media codecs and proprietary software are included in mint but was absent in Ubuntu. But now it has its own popularity and it uses cinnamon and mate desktop instead of Ubuntu's unity desktop environment.

Debian:

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Debian has its existence since 1993 and releases its versions much slowly then Ubuntu and mint.

This makes it one of the most stable Linux distributor.

Ubuntu is based on Debian and was founded to improve the core bits of Debian more quickly and make it more user friendly. Every release name of Debian is based on the name of the movie Toy Story.

Red Hat Enterprise / CentOS:

Red hat is a commercial Linux distributor. There products are red hat enterprise Linux (RHEL) and Fedora which are freely available. RHEL is well tested before release and supported till seven years after the release, whereas, fedora provides faster update and without any support.

Red hat uses trademark law to prevent their software from being redistributed. CentOS is a community project that uses red hat enterprise Linux code but removes all its trademark and make it freely available. In other words, it is a free version of RHEL and provide a stable platform for a long time.

Fedora:

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It is a project that mainly focuses on free software and provides latest version of software. It doesn't make its own desktop environment but used 'upstream' software. By default it has GNOME3 desktop environment. It is less stable but provides the latest stuff.

7. Is Linux open source 🙄

Linux is a free, open source operating system, released under the GNU General Public License (GPL). Anyone can run, study, modify, and redistribute the source code, or even sell copies of their modified code, as long as they do so under the same license.

Linux has become the largest open sources software project in the world. Professional and hobbyist programmers and developers from around the world contribute to the Linux kernel, adding features, finding and fixing bugs and security flaws, live patching, and providing new ideas—all while sharing their contributions back to the community.

8. Advantages of using linux OS

The software updates in Linux are easy and frequent.
Various Linux distributions are available so that you can use them according to your requirements or according to your taste.
Linux is freely available to use on the internet.
It has large community support.
It provides high stability. It rarely slows down or freezes and there is no need to reboot it after a short time.
It maintain the privacy of the user.
The performance of the Linux system is much higher than other operating systems. It allows a large number of people to work at the same time and it handles them efficiently.
It is network friendly.