1. Linux Overview Date: 18/09/2016 1

2. Outline 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 2

3. 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. 3

4. User1User4User2User3 CompilerAssemblerText Editor Database System System and Application Programs Operating System Computer Hardware 4

5. 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 5

6. 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. User interface Program execution I/O operations File-system manipulation Communications Error detection Resource allocation Accounting Protection and security 6

7. 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. 7

8. 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. 8

9. 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. 9

10. 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. 10

11. 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" 11

12. Differences between Windows and Linux LinuxWindows Full AccessNo Access Licensing FreedomLicensing Restriction Online Peer SupportPaid Help-Desk Support Partial Hardware SupportFull Hardware Support Command LineNo Command Line CentralizedNo centralized Application Installation FlexibilityRigidity 12

13. 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. 13

14. 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. 14

15. References How Linux Works 2 nd Edition (2014) Operating System Concepts 7 th Edition Linux + Complete Study Guide 15

16. 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. 16

17. جرأت کن و به بهترین کسی که میتوانی تبدیل شو! Courage and become the best person you can be! 17