THEORY-110 :- INTRODUCTION TO LINUX AND ITS STRUCTURES

Linux Operating System

An operating system can be described as an interface among the computer hardware and the user of any computer. It is a group of software that handles the resources of the computer hardware and facilitates basic services for computer programs.

An operating system is an essential component of system software within a computer system. The primary aim of an operating system is to provide a platform where a user can run any program conveniently or efficiently.

On the other hand, Linux

Linux  is  a  UNIX –like  and  mostly  POSIX  non resistant  computer  operating  system.  Linux  kernel  was first  released  on  5  October  1991  by  Linus  Torvald,  a graduate  Technology  in  Finland.  Since  it  was  written from scratch, it does not contain any behavior code. It is assembled  under  the  model  of  free  and  open  source software development and distributes. Linux is an leading operating system on server and other big systems such as mainframe  computers  and  fastest super computer. It also runs on the coordinated system which devices having OS is  typically  built  into  a  microcode,  it  includes  smart phones,   tablets   running   android,   Linux   derivatives, network   routers,   televisions,   video   games   and   smart watches.  The  source  code  may  be  used,  modified  and distributed with respective license as GNU general public license.  Some  of  the  popular  Linux  distributions  are DEBIAN,  UBUNTU,  LINUX  MINT,  FEDORA,  ARCH LINUX, RED HAT and SUSE Linux organization server

Architecture of Linux system

The Linux operating system's architecture mainly contains some of the components: the Kernel, System Library, Hardware layer, System, and Shell utility.

Kernel:- The kernel is one of the core section of an operating system. It is responsible for each of the major actions of the Linux OS. This operating system contains distinct types of modules and cooperates with underlying hardware directly. The kernel facilitates required abstraction for hiding details of low-level hardware or application programs to the system. There are some of the important kernel types which are mentioned below:

1. Monolithic Kernel
2. Micro kernels
3. Exo kernels
4. Hybrid kernels

System Libraries:- These libraries can be specified as some special functions. These are applied for implementing the operating system's functionality and don't need code access rights of the modules of kernel.

System Utility Programs:- It is responsible for doing specialized level and individual activities.

Hardware layer:- Linux operating system contains a hardware layer that consists of several peripheral devices like CPU, HDD, and RAM.

Shell:- It is an interface among the kernel and user. It can afford the services of kernel. It can take commands through the user and runs the functions of the kernel. The shell is available in distinct types of OSes. These operating systems are categorized into two different types, which are the graphical shells and command-line shells.

The graphical line shells facilitate the graphical user interface, while the command line shells facilitate the command line interface. Thus, both of these shells implement operations. However, the graphical user interface shells work slower as compared to the command-line interface shells.

There are a few types of these shells which are categorized as follows:

1. Korn shell
2. Bourne shell
3. C shell
4. POSIX shell

FEATURES OF LINUX

• Linux is inexpensive , Fast, Stable and Open-Source Software
• Portable: Linux OS can perform different types of hardware and the kernel of Linux supports the installation of any type of hardware environment.
• Multiprogramming: Linux OS can be defined as a multiprogramming system. It means more than one application can be executed at the same time.
• Multi-user: Linux OS can also be defined as a multi-user system. It means more than one user can use the resources of the system such as application programs, memory, or RAM at the same time.
• Hierarchical file system: Linux OS affords a typical file structure where user files or system files are arranged.
• Security: Linux OS facilitates user security systems with the help of various features of authentication such as controlled access to specific files, password protection, or data encryption.
• Shell: Linux operating system facilitates a unique interpreter program. This type of program can be applied for executing commands of the operating system. It can be applied to perform various types of tasks such as call application programs and others.

DRAWBACKS OF LINUX

• Security ,Lack of Support And Limited Software Selection Choice 

Let's take the Photoshop example which is a famous tool for graphic editing. Photoshop exists for Windows; however, it is not available in Linux. Also, there are some other tools for photo editing but the Photoshop tool is more powerful as compare to others. Another example is MS office which is not present for Linux users.

• Limited Hardware Support 

Most of the users of Linux face an issue while using Linux. Various companies of hardware prefer to build drivers for Mac or Windows due to they contain several users than Linux. Linux has small drivers for peripheral hardware than windows.

• Complexity 

Linux isn't a very user-friendly operating system. Hence, it might be confusing for many beginners. Getting begun with Windows is efficient and easy for many beginners; however, understanding Linux working is complex. 

We have to understand the command line interface and finding for newer software is a little bit complex as well. When we face any issue in the OS, the searching solution is very problematic. Also, there are various experts for Mac and Windows as compare to Linux.

• Games: Several games are developed for Windows but unfortunately not for Linux. Because the platform of Windows is used widely. So, the developers of the games are more interested in windows.

Linux Operating System Applications

Linux is a billion-dollar corporation nowadays. Thousands of governments and companies are using Linux operating system across the world because of lower money, time, licensing fee, and affordability. Linux can be used within several types of electronic devices. These electronic devices are easily available for users worldwide. A few of the famous Linux-based electronic devices are listed below:

• Yamaha Motive Keyboard
• Volvo In-Car Navigation System
• TiVo Digital Video Recorder
• Sony Reader
• Sony Bravia Television
• One Laptop Per child XO2
• Motorola MotoRokr EM35 phone
• Lenovo IdeaPad S9
• HP Mini 1000
• Google Android Dev Phone 1
• Garmin Nuvi 860, 880, and 5000
• Dell Inspiron Mini 9 and 12