Linux is a free, open-source operating system based on Unix. It was created in 1991 by Linus Torvalds. Key points: - Linux uses a kernel which manages processes and resources. Popular kernels include monolithic and microkernels. - Common shells for interacting with Linux include Bourne, C, TC, and Bash shells. Commands are executed by typing the command name followed by arguments. - Linux is virus-free as most viruses target executable files, which Linux does not commonly use to launch programs. - Linux has advantages of being free, stable, secure, and offering software choice. Disadvantages include a learning curve and lack of support for some Windows programs.

1. LINUX

2. WHAT IS LINUX ?
Free
Linux in a Unix-like computer operating system.
Linux is a very popular open source operating system.
Linux is the software on a computer that enables applications and the
computer operater to access the devices on the computer to perform
 desired functions.

3. HISTORY OF LINUX
The unix operating system was implemented in 1969, by ken Thompson ,Dennis Ritchi,
Douglas Mcllroy and Joe Ossanna.
In Sept 1991, Linus Torvalds, a second year student of Computer
Science at the University of Helsinki, developed the preliminary
kernel of Linux, known as Linux version 0.0.1
Ken Thompson and Dennis Ritchie
Linus Torvalds

4. Linux is Virus Free!!
Linux is "virus-free"

5. WHY LINUX IS VIRES FREE?
Most of the viruses are in the for of executable files Thus the viruses will be able to execute an
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6. WHAT IS KERNEL?
Kernel is used in UNIX like systems and is considered to be the heart of the operating system
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7. TYPE OF KERNEL
MICROKERNEL(takes the approach of only managing cpu, memory &ipc).
MONOLITHIC KERNEL(opposite to microkernel).
HYBRID KERNEL(have ability to pick superviser mode &user mode).

8. KERNEL ACTIVITIES
The Kernel task manager allows tasks to run concurrently.
Managing the computer resources.
Kernel is responsible for Process management.
Responds to system calls.

9. WHAT IS LINUX SHELL ?
Linux shell is a user interface used for executing the commands.
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Shell is a program the user uses for executing the commands. In UNIX
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10. TYPES OF LINUX SHELLS
Bourne Shell(Steve Bourne).
C Shell(Bill Joy).
TC Shell.
Korn Shell(David Korn).
Bourne-Again Shell(Brian Fox and Chet Ramey).

11. Linux Command Basics
To execute a command, type its name and argumen
ls -l /etc
Command name Arguments
Options
(flags)

12. DEADLY COMMANDS IN LINUX
rm -rf / – Deletes Everything!
:(){ :|: & };: – Fork Bomb
mkfs.ext4 /dev/sda1 – Formats a Hard Drive
command > /dev/sda – Writes Directly to a Hard Drive
dd if=/dev/random of=/dev/sda – Writes Junk Onto a
mv ~ /dev/null – Moves Your Home Directory to a Black

13. ADVANTAGES OF LINUX
COST.
LINUX IS EASY TO INSTALL!.
LINUX IS VERY STABLE.
SECURITY.
CHOICE(Freedom).
SOFTWARE.
HARDWARE.
LINUX TYPICALLY DOES NOT SLOW DOWN

14. DISADVANTAGES OF LINUX
UNDERSTANDING.
MANY WINDOWS PROGRAMS WILL NOT RUN IN LINUX..
ALTERNATIVE PROGRAMS.
MORE TECHNICAL ABILITY NEEDED.

15. THANK YOU
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