Download Linux Overview

Linux Overview
Date: 18/09/2016
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Outline
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What is Operating System
Operating System Services
Types of Operating System
Parts of Operating System
Introduction to Linux
Linux History
Differences between Linux and Windows
Licensing Facts
References
Assignment
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What is Operating System
• Operating systems are an essential part of any computer system.
• An operating system acts as an intermediary between the user of a
computer and the computer hardware.
• The purpose of an operating system is to provide an environment in
which a user can execute programs in a convenient and efficient
manner.
• An operating system is software that manages the computer
hardware.
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User1
Compiler
User2
Assembler
User3
Text Editor
User4
Database System
System and Application Programs
Operating System
Computer Hardware
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Continue…
• Because an operating system is large and complex, it must be created piece
by piece.
• The hardware the central processing unit (CPU), the memory, and the
input/output (I/O) devices provides the basic computing resources for the
system.
• The application programs such as word processors, spreadsheets,
compilers, and web browsers define the ways in which these resources are
used to solve users' computing problems.
• Operating systems allocate the resources for application and resources in
two manners.
• Time sharing
• Multiplexing
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Operating-System Services
• An operating system provides an environment for the execution of
programs.
• It provides certain services to programs and to the users of those
programs.
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User interface
Program execution
I/O operations
File-system manipulation
Communications
Error detection
Resource allocation
Accounting
Protection and security
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Types of Operating Systems
Batch operating system: The users of a batch operating system do not
interact with the computer directly.
Time-sharing operating systems: Time-sharing is a technique which
enables many people, located at various terminals, to use a particular
computer system at the same time.
Distributed operating System: Distributed systems use multiple central
processors to serve multiple real-time applications and multiple users.
Data processing jobs are distributed among the processors accordingly.
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Continue…
• Network operating System: A Network Operating System runs on a
server and provides the server the capability to manage data, users,
groups, security, applications, and other networking functions.
• Real Time operating System: A real-time system is defined as a data
processing system in which the time interval required to process and
respond to inputs is so small that it controls the environment.
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Parts of Operating System
• Kernel: This has the task of loading the applications into memory, making
sure they do not interfere with one another and allowing them to share
use of the CPU efficiently.
• User interface: This part of the operating system is directing what you see
on the screen and reacting to your key presses and other inputs. The user
interface could be a basic command line interface, as you might find on a
server, or it might be a full blown Graphical User Interface (GUI) such as the
Mac OS X, Windows or perhaps Gnome on Linux.
• File Systems: A file system is the methods and data structures that an
operating system uses to keep track of files on a disk or partition; that is,
the way the files are organized on the disk.
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Introduction to Linux
• Linux is an open source operating system.
• Linux is developed collaboratively.
• This spreading of development burden amongst individuals and
companies has resulted in a large and efficient ecosystem and
unheralded software innovation.
• Linux, which began its existence as a server OS and has become useful
as a desktop OS, can also be used on all of these devices.
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Linux History
• Linux Torvalds was a student in Helsinki, Finland in 1991 when he
started a project writing his own operating system.
• As Torvalds wrote in his book Just for Fun, he eventually ended up
writing an operating system kernel. On 25 August 1991.
• He (at age 21) announced this system in a Usenet posting to
the newsgroup "comp.os.minix.
• Torvalds' coworker at the Helsinki University of Technology (HUT) who
was one of the volunteer administrators for the FTP server at the
time, did not think that "Freax" was a good name. So, he named the
project "Linux"
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Differences between Windows and Linux
Linux
Windows
Full Access
No Access
Licensing Freedom
Licensing Restriction
Online Peer Support
Paid Help-Desk Support
Partial Hardware Support
Full Hardware Support
Command Line
No Command Line
Centralized
No centralized Application Installation
Flexibility
Rigidity
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Licensing Facts
• In most case, when you obtain or buy software, you really do not own
it. Rather you are granted a license to use the software.
• Open Source: Software that is distributed with the source files. End
users can modify and recompile the software to meet their needs.
• Closed Source: software that is distributed without the source files.
Many commercially available software is closed source (Windows,
Excel … ).
• Freeware: Software distributed without cost. The software may be
open source or closed source.
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Continue…
• Free Software: Software that is freely distributable, includes the source
code, and allows the end user to modify or enhance the software.
• Free software maybe distributed at a cost. The free refers to the freedom of use, not
necessarily no cost.
• Shareware: Software that is distributed free of cost on a trail or limited use
basis. Shareware is typically closed source software.
• Artistic License: Artistic license is a type of licensing agreement that allows
users to modify and distribute open source software, while still retaining
some degree of copyright protection for the work being distributed. The
GNU General Public License is an example of artistic license.
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References
• How Linux Works 2nd Edition (2014)
• Operating System Concepts 7th Edition
• Linux + Complete Study Guide
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Assignment
• Linux foundation and its responsibilities.
• What are the file systems used by Linux Operating Systems.
• Define Linux Operating system’s boot process.
• What is boot loader.
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