Linux is an open source operating system created by Linus Torvalds in 1991. There are various Linux distributions like Red Hat, Ubuntu, and Android that offer different desktop environments and software. While Linux is free and open source, vendors make money through support services, commercial licenses, or annual subscription fees. The command line interface and root user privileges give Linux more power and flexibility than typical desktop operating systems.

1. Introduction to Linux

2. What is Linux?
• Linux is an OS.
• OS is software layer that is between the
hardware and software(application). OS is
what allows the software to talk to the
hardware. e.g Print a file, write a file , etc.
• Created between 1991 to 1994 by Linus
Trovalds.

3. What is Linux?
• Linux is not Unix(Similar sounding …ux).
• 1990s Unix was a paid OS so was Microsoft
• Linux created it from scratch as he wanted a
free open source OS.

4. Linux Distro
• Since code was open source people started
creating their own flavors of Linux.
• Various versions of linux created are called
distros . E,g Red Hat, Ubuntu, Google
Andriod(mobile phones) are different distros.
• While selecting what distro to use u must
decide what u want your computer to do
before you install your OS.

5. Linux Distro
• In Linux every distro is built to do things in a
certain way.
• Few Distros: Trustix Linux (most secure-solid
brick ) or Ubuntu for Desktop(Normal use) or
Red Hat for Enterprise or DSL(Damm Small
Linux) only 53 MB .

6. Open Source License
• Does open source software mean free
Software?

7. Open Source License
• It’s a wrong idea.
• Open source software means that the
programmers provide you with the code so
that you can see how the program was
written.
• Lets see how these vendors get paid. There
are four different ways.

8. Open Source License
• Lets see how these vendors get paid. There are four
different ways.
 Software is given utterly free(Mysql model) but when
you need help their services need to be paid.(e.g
training, troubleshooting, etc).
Software is free for personal and non-commercial use.
As soon as you use it for commercial purpose you have
to pay. You can set up a network server in a lab but as
soon as you used it in a production environment you
have to pay a licensing fee which can be a huge amount.

9. Open Source License
• Contd.
Software is sold as everyone sells it and the
difference from that with windows is you can still
see the source code. However you don’t have right
to modify the code(copyright issue).
Software is given for free. However the license
states in order to use the software you have to pay
a reoccurring contract( e,g to use redhat pay 100$
to 1000$ as annual fees…subscription contract).

10. The Shell
• It is the screen you use to interact with the
OS.
• Windows is GUI shell or LUI shell(DOS
prompt) while in Linux mostly LUI shell is used
which is more powerful shell.

11. ROOT
• Biggest concept of Linux.
• Highest level user you can be. It is like an
administrator in windows.
• If you log in as root you can do anything.
• Linux root is represented as while in
windows it is C:/. It is where the OS resides.

12. Capitalization
• Upper case or Lower case letters.
• Windows doesn’t care except for passwords. i.e
Home=home=HoMe=hoME.
• Linux was created by and for computer
professionals, computer scientists and technical
people. Here home dir is different from Home dir.
All letters are represented as ASCII text and H is a
different character then that of h.

13. Server vs Desktop
• Main difference: Server version is a striped
down version of the Desktop version.
• It is because it is assumed that if you want to
install a server you know what you want from
it. There will be no tools or GUI. You have to
downlaod and install whatever you require.
• Best install desktop version if you are new to
Linux because it has GUI.

14. Why use Linux?
• Linux is good for something and crap for
something.
• As a desktop OS it is slow and freezes up
frequently.
• Very good for server functionality. It is a rock
solid once installed it will just keep on running
without any flaws.