Linux IntroductionPresenter: Abdikarim Abdullahiarim Abdullahi

What is Linux Operating System

All computers rely on an operating system (OS) to provide the interface for interaction between users, applications, and hardware.

The operating system boots the computer and manages the file system.

Operating System instructs the computer how to operateThe operating system (OS) controls almost all functions on a computer

The operating system has four main roles: Control hardware access Manage files and folders Provide user interface Manage applications

Just like Windows XP, Windows 7, Windows 8, and Mac OS X, Linux is an operating system. An operating system is software that manages all of the hardware resources associated with your desktop or laptop.

To put it simply – the operating system manages the communication between your software and your hardware. Without the operating system (often referred to as the “OS”), the software wouldn’t function.

The operating system (OS) is the program which starts up when you turn on your computer and runs underneath all other programs - without it nothing would happen at all.

In simple terms, an operating system is a manager. It manages all the available resources on a computer, from the CPU, to memory, to hard disk accesses.

Tasks the operating system must perform: Control Hardware - The operating system controls all the parts of the computer

and attempts to get everything working together. Run Applications - Another job the OS does is run application software. This

would include word processors, web browsers, games, etc... Manage Data and Files - The OS makes it easy for you to organize your

computer. Through the OS you are able to do a number of things to data, including copy, move, delete, and rename it. This makes it much easier to find and organize what you have.

Types of operating systems Operating systems usually come preloaded on any computer you buy. Most people

use the operating system that comes with their computer, but it is possible to upgrade or even change operating systems.

The three most common operating systems for personal computers are Microsoft Windows, Mac OS X, and Linux.

Modern operating systems use a Graphical User Interface, or GUI (pronounced "gooey"). A GUI lets you use your mouse to click on icons, buttons, and menus, and everything is clearly displayed on the screen using a combination ofgraphics and text.

Each operating system's GUI has a different look and feel, so if you switch to a different operating system it may seem unfamiliar at first. However, modern operating systems are designed to be easy to use, and most of the basic principles are the same.

In the images below, you can see the Windows and Mac OS X GUIs.

Microsoft Windows

Microsoft created the Windows operating system in the mid-1980s. Over the years, there have been many different versions of Windows, but the most recent ones are Windows 8 (released in 2012), Windows 7 (2009), and Windows Vista (2007). Windows comes preloaded on most new PCs, which helps to make it the most popular operating system in the world.

If you're buying a new computer or upgrading to a newer version of Windows, you can choose from several different editions of Windows, such as Home Premium, Professional, and Ultimate. You may need to do some research to decide which edition is right for you.

Apple Mac OS X

Mac OS is a line of operating systems created by Apple Inc. It comes preloaded on all new Macintosh computers, or Macs. All of the recent versions are known as OS X (pronounced O-S Ten), and the specific versions include Mavericks(released in 2013), Mountain Lion (2012), Lion (2011), and Snow Leopard (2009). Apple also offers a version called Mac OS X Server, which is designed to be run on servers.

Operating systems for mobile devices The operating systems we've been talking about were designed to

run on desktop or laptop computers.  Mobile devices such as phones, tablet computers, and mp3 players

are different from desktop and laptop computers, so they run operating systems that are designed specifically for mobile devices. Examples of mobile operating systems include Apple iOS, Windows Phone, and Google Android.

Linux Linux (pronounced LINN-ux) is a family of open-source operating systems, which

means they can be modified and distributed by anyone around the world. This is different from proprietary software like Windows, which can only be modified by the company that owns it (Microsoft).

The advantages of Linux are that it is free, and there are many different distributions (or versions) you can choose from. Each distribution has a different look and feel, and the most popular ones include Ubuntu, Mint, and Fedora.

Linux is named after Linus Torvalds, who created the Linux kernel in 1991. The kernel is the computer code that is the central part of an operating system.

Before Linux In 80’s, Microsoft’s DOS was the dominated OS for PC Apple MAC was better, but expensive UNIX was much better, but much, much more expensive. Only for

minicomputer for commercial applications People was looking for a UNIX based system, which is cheaper

and can run on PC Both DOS, MAC and UNIX were proprietary, i.e., the source code

of their kernel is protected No modification is possible without paying high license fees

GNU project Established in 1984 by Richard Stallman, who believes that software should be free

from restrictions against copying or modification in order to make better and efficient computer programs

GNU is a recursive acronym for “GNU's Not Unix” Aim at developing a complete Unix-like operating system which is free for copying and modificationCompanies make their money by maintaining and distributing the software, e.g. optimally packaging the software with different tools (Redhat, Slackware, Mandrake, SuSE, etc)Stallman built the first free GNU C Compiler in 1991. But still, an OS was yet to be developed

Beginning of Linux A famous professor Andrew Tanenbaum developed Minix, a simplified version of

UNIX that runs on PC

Minix is for class teaching only. No intention for commercial use In Sept 1991, Linus Torvalds, a second year student of Computer Science at the

University of Helsinki, developed the preliminary kernel of Linux, known as Linux version 0.0.1

Linux Today

Linux has been used for many computing platforms– PC, PDA, Supercomputer,…

Not only character user interface but graphical user interface is available Commercial vendors moved in Linux itself to provide freely distributed code. They

make their money by compiling up various software and gathering them in a distributable format

– Red Hat, Slackware, etc

In order to encourage wide dissemination of his OS, Linus made the source code open to public. At the end of 1992 there were about a hundred Linux developers. Next year there were 1000. And the numbers multiplied every year.

Recent estimates say about 29 million people use Linux worldwide. The effects of the dot-com bust, IT slowdown and global economic recession can be clearly seen.

If you run Linux, add your machine at Linux Counter

Source: The Linux Counter

Linux: No of Users

Growing and growing…

So the question is, why shift to Linux?

Shelling out money for a computer and then more for an operating system sounds costly to anyone especially if there are alternatives.

Windows requires users to pay licensing fees and other extended fees to maximize its features while Linux is being distributed for free or sometimes at a minimal fee from other distribution companies.

Also, in terms of multi-users, Windows is only allowed to be installed and run on a single computer unless you pay for another license,unlike Linux which allows multi-user installation with no additional cost.

Users who are considering making a change from Windows to Linux or Linux to Windows commonly want to know the advantages and disadvantages of each of theoperating systems. Below is a chart to help illustrate the major advantages and disadvantages of each of these operating systems.

Topic Linux Windows

Price The majority of Linux variants are available for free or at a much lower price than Microsoft Windows.

Microsoft Windows can run between $50.00 - $150.00 US dollars per each license copy.

Ease Although the majority Linux variants have improved dramatically in ease of use, Windows is still much easier to use for most computer users because of the familiarity of Windows and because it's more likely they are using a Windows computer at home, in school, or at the office.

Microsoft has made several advancements and changes that have made it a much easier to use operating system, and although arguably it may not be the easiest operating system, it is still Easier than Linux.

Linux vs Windows

Reliability

The majority of Linux variants and versions are notoriously reliable and can often run for months and years without needing to be rebooted.

Although Microsoft Windows has made great improvements in reliability over the last few versions of Windows, it still cannot match the reliability of Linux.

Software

Linux has a large variety of available softwareprograms, utilities, and games. However, Windows has a much larger selection of available software.

Because of the large amount of Microsoft Windows users, there is a much larger selection of availablesoftware programs, utilities, and games for Windows.

Software Cost

Many of the available software programs, utilities, and games available on Linux arefreeware or open source. Even such complex programs such as Gimp, OpenOffice,StarOffice, and wine are available for free or at a low cost.

Although Windows does havesoftware programs, utilities, and games for free, the majority of the programs will cost anywhere between $20.00 - $200.00+ US dollars per copy.

Hardware

Although hardware manufacturers have made great advancements in supporting Linux it still will not support most hardware devices. However, for the hardware devices that have driver support they usually work in all versions of Linux.

Because of the amount of Microsoft Windows users and the broader driver support, Windows has a much larger support for hardware devices and almost all hardware manufacturers will support their products in Microsoft Windows.

Security

Linux is and has always been a very secure operating system. Although it still can be attacked when compared to Windows, it much more secure.

Although Microsoft has made great improvements over the years with security on their operating system, their operating system continues to be the most vulnerable to viruses and other attacks.

Linux Distributions:

Red Hat Linux : One of the original Linux distribution.The commercial, nonfree version is Red Hat Enterprise Linux, which is aimed at big companies using Linux servers and desktops in a big way. Free version: Fedora Project.

Debian GNU/Linux : A free software distribution. Popular for use on servers. However, Debian is not what many would consider a distribution for beginners, as it's not designed with ease of use in mind.

SuSE Linux : SuSE was recently purchased by Novell. This distribution is primarily available for pay because it contains many commercial programs, although there's a stripped-down free version that you can download.

Mandrake Linux : Mandrake is perhaps strongest on the desktop. Originally based off of Red Hat Linux.

Gentoo Linux : Gentoo is a specialty distribution meant for programmers.