Unix is a multi-user, multi-tasking operating system that was first created in 1969 at Bell Labs. It allows many users to use the system simultaneously running multiple programs. Linux originated in 1991 as a personal project and is now a free, open source Unix-like operating system. It features multi-tasking, virtual memory, networking and more. Linux is widely used for servers, workstations, internet services and more due to its low cost, stability, and reliability compared to other operating systems.

1. Presentation on introduction of UNIX
Submitted To:
Mr.Nitesh Baghel
Miss.Rohini Chouhan
Submitted by:
Sudhir kumar saurav
0158cs111101

2. Introduction to Linux
UNIX
Unix is a multi-user, multi-tasking operating system.
You can have many users logged into a system
simultaneously, each running many programs.
It's the kernel's job to keep each process and user separate
and to regulate access to system hardware, including cpu,
memory, disk and other I/O devices.

3. Introduction to Linux
HISTORY OF UNIX
First Version was created in Bell Labs in 1969.
Some of the Bell Labs programmers who had worked on
this project, Ken Thompson, Dennis Ritchie, Rudd Canaday,
and Doug McIlroy designed and implemented the first
version of the Unix File System on a PDP-7 along with a
few utilities. It was given the name UNIX by Brian
Kernighan.
00:00:00 Hours, Jan 1, 1970 is time zero for UNIX. It is also
called as epoch.

4. Introduction to Linux
HISTORY OF UNIX
1973 Unix is re-written mostly in C, a new language
developed by Dennis Ritchie.
Being written in this high-level language greatly decreased
the effort needed to port it to new machines.
1977 There were about 500 Unix sites world-wide.
1980 BSD 4.1 (Berkeley Software Development)
1983 SunOS, BSD 4.2, System V

5. Introduction to Linux
HISTORY OF UNIX
1988 AT&T and Sun Microsystems jointly develop System V
Release 4 (SVR4). This later developed into UnixWare and
Solaris 2.
1991 Linux was originated.

6. Introduction to Linux
WHAT IS LINUX
Linux is a free Unix-type operating system originally
created by Linus Torvalds with the assistance of developers
around the world.
It originated in 1991 as a personal project of Linus
Torvalds, a Finnish graduate student.
The Kernel version 1.0 was released in 1994 and today the
most recent stable version is 2.6.9
Developed under the GNU General Public License , the
source code for Linux is freely available to everyone.

7. Introduction to Linux
UNIX STRUCTURE

8. LINUX FEATURES
• UNIX-like operating system.
• Features:
• Preemptive multitasking.
• Virtual memory (protected memory, paging).
• Shared libraries.
• Demand loading, dynamic kernel modules.
• Shared copy-on-write executables.
• TCP/IP networking.
• SMP support.
• Open source.

9. HISTORY
• UNIX: 1969 Thompson & Ritchie AT&T Bell Labs.
• BSD: 1978 Berkeley Software Distribution.
• Commercial Vendors: Sun, HP, IBM, SGI, DEC.
• GNU: 1984 Richard Stallman, FSF.
• POSIX: 1986 IEEE Portable Operating System unIX.
• Minix: 1987 Andy Tannenbaum.
• SVR4: 1989 AT&T and Sun.
• Linux: 1991 Linus Torvalds Intel 386 (i386).
• Open Source: GPL.

10. WHAT’S A KERNEL?
• AKA: executive, system monitor.
• Controls and mediates access to hardware.
• Implements and supports fundamental abstractions:
• Processes, files, devices etc.
• Schedules / allocates system resources:
• Memory, CPU, disk, descriptors, etc.
• Enforces security and protection.
• Responds to user requests for service (system calls).
• Etc…etc…

11. WHERE IS LINUX USED?
 75% of respondents were already using Linux and another 14% were
evaluating it
 43% of all web sites use Linux servers running the Apache Web server

12. HOW IS LINUX USED?
 Personal Workstation
 File and Print Server
 Internet Service Provider
 Three-tier Client/Server
 Turnkey System

13. WHY USE LINUX?
• Costs less
• Stable
• Reliable
• Extremely powerful

15. • Financial Differences
• Technical Differences
• End-User Differences

16. LINUX VS. WINDOWS
COST
LINUX WINDOWS
Online Downloads Free Not Available
Retail Price, CD $50 $300

17. Technical Differences

18. LINUX VS. WINDOWS
Keeping up to date
By Upgrading
Linux upgrades faster than Windows
Compatibility
Linux is Backward Compatible unlike Windows

19. LINUX VS. WINDOWS
• Application Differences
 No commercial word processor for Linux, which matches the quality for
Windows

20. End-User Differences

21. • Proprietary vs. Open Source
 Windows is a Proprietary Technology
Applications will only work on Windows
 Linux – Open Source

22. LINUX
 Complete information needed for download
 Technical help – Available on Internet (user must be comfortable with UNIX
system)
 Windows word processor is better than Linux

23. LINUX VS. WINDOWS
 Head to head competition
 Used side by side as servers
 Both handled daily workload for several small business operations
 Linux with hardware disadvantage supported a community of users 3 times size of
NT’s
In The Commercial Arena

24. CONCLUSION
“When is it best to use Linux and when should some other operating system be
preferred?”
 It all depends on the user.