Ubuntu is a Debian-based Linux operating system with Unity as its default desktop. It contains software like LibreOffice, Firefox, and Thunderbird by default and supports additional software via its software center. Ubuntu aims to be secure out of the box with user programs running with low privileges. It uses GRUB as its bootloader and EXT4 as its default file system. Software can be installed and managed through the software center or via terminal commands. Ubuntu is generally considered virus free and safe due to its architecture and lack of widespread malware.

2. Introduction
 Ubuntu is a Debian-based Linux operating system, with Unity as its
default desktop environment. It is based on free software and
named after the Southern African philosophy of ubuntu
 Development of Ubuntu is led by UK-based Canonical Ltd., a
company owned by South African entrepreneur Mark Shuttleworth

3. Features of Ubuntu
 A default installation of Ubuntu contains a wide range of software
that includes LibreOffice, Firefox, Thunderbird, Transmission, and
several lightweight games such as Sudoku and chess
 GIMP, Pidgin, and Synaptic, are accessible from the built in Ubuntu
Software Center as well as any other APT based package
management tool. Execution of Microsoft Office and other
Microsoft Windows applications can be facilitated via the Wine
compatibility package or through the use of a virtual machine such
as VirtualBox or VMware Workstation

4. Security
 Ubuntu's goal is to be secure "out-of-the box". By default, the user's
programs run with low privileges and cannot corrupt the operating
system or other user's files
 It has Sandbox technology

5. Boot Loader
 Ubuntu uses GRUB which is developed under GNU
project
 It will generate boot loading entries residing inside MBR
 GRUB config file:/boot/grub/grub.config

6. How GRUB Works?
 First thing;’s first Boot.img is loded at the initial stage which is an
essential file for booting which generates core.img
 Core.img is used to load the rest of the files

7. Desktop enviroments on Ubuntu
 KDE:more functionality,higher Ram usage than other,
animations,etc
 GNOME:Compact,slicky,easy to use
 XFCE:Easy to use,faster,low power usage etc.
 LXDE:very light compact,light RAM usage, very low power
consumption

8. File System in ubuntu
 Ubuntu uses EXT journaling file system
 An advantage of the journaling file system is that it’s
atomic in nature
 ALL or None principle is followed
 Types of Journaling partitions ext2,ext3,ext4

9. Software Management
 Software can be installed and uninstalled using Ubuntu
software center
 Software run on user level
 Software can also be installed using terminal by using
sudo –apt install “software name”

10. Virus Free!!!
 Most linux system are safe and secure
 Most Trojan and viruses are blocked
 Firestarter can be used as firewall and clam TK can be
used as antivirus scanner

11. Third-party software
 Ubuntu has a certification system for third-party
software.Some third-party software that does not limit
distribution is included in Ubuntu's multiverse
component. The package ubuntu-restricted-extras
additionally contains software that may be legally
restricted, including support for MP3 and DVD playback,
Microsoft TrueType core fonts
 Adobe flash plugin cannot be used!!!

12. Version Code name Release date
Supported until
Desktop Server
10.04 LTS Lucid Lynx 2010-04-29
Old version, no
longer supported:
2013-05-09
Older version, yet still
supported: 2015-04-
30
10.10 Maverick Meerkat 2010-10-10
Old version, no longer supported: 2012-04-
10
11.04 Natty Narwhal 2011-04-28
Old version, no longer supported: 2012-10-
28
11.10 Oneiric Ocelot 2011-10-13
Old version, no longer supported: 2013-05-
09
12.04 LTS Precise Pangolin 2012-04-26 Older version, yet still supported: 2017-04
12.10 Quantal Quetzal 2012-10-18
Old version, no longer supported: 2014-05-
16
13.04 Raring Ringtail 2013-04-25
Old version, no longer supported: 2014-01-
27[28]
13.10 Saucy Salamander 2013-10-17
Old version, no longer supported: 2014-07-
17
14.04 LTS[62] Trusty Tahr 2014-04-17 Older version, yet still supported: 2019-04

13. Ubuntu Touch
 Ubuntu Touch is an alternate version of Ubuntu
developed for smartphones and tablets which was
announced on 2 January 2013. Ubuntu Touch was
Released To Manufacturing on 16 September 2014 The
first device to run it was the Galaxy Nexus