What is Linux ?
1. Linux is an operating system
2. Linux is a clone of UNIX operating systems but unlike many versions of UNIX, most versions of Linux are free
3. Linux was designed to run on a PC
4. Linux is multi-tasking & multi-user
5. Linux is robust and scaleable
6. Linux is stable
7. Linux is open-source
8. Linux is portable (PDA, cell phone, Car, appliances)
9. Linux is secure
History of Linux:
In 1991, Linus Torvalds, a student at the University of Helsinki in Finland, developed the Linux Kernel. It was released on the internet and was freely available for download. Back in 1983, the Free Software Foundation (www.fsf.org) began developing open-source software to create a free UNIX operating system. This software was called the GNU (guh-noo) utilities. GNU stands for “GNU’s not Unix” Around 1991, the GNU utilities were combined with the Linux Kernel.
Today, most people call this operating system Linux. However, the Free Software
Foundation says that it is incorrect and it should be called GNU/Linux.
You should know that the Linux Source and most applications for it are free of charge. So any company charging you for linux is not charging you for the software but, instead, for the compiling of the software, the packaging and support of the software.GNU Mascot — Mountain Goat (GNU) and Linux Mascot — Penguin (TUX)
When RedHat released its fully package version of Linux with support its popularity took off. Soon after that, commercial vendors like IBM, Dell and HP began pushing Linux on servers. Linux continues to increase popularity more and more mainstream computer users.
Important Linux Licensing Information:
Linux is the most important part of the Open Source Software Movement. Linux is legally covered by the GNU General Public License (GPL). Open Source Software is free, but it is not in the public domain. It is not shareware either. GPL allows people to take free software and distribute their own versions of the software. However the vendors who sell free software cannot restrict the rights of users who purchase the software. In other words, users who buy GPL software can make copies of it and distribute it free of charge or for a fee. Also, distributors of GPL software must make it clear that the software is covered by the GPL and must provide the complete source code for the software at no cost. Linux is the perfect example of how this is supposed to work.
Types Of Linux Distributions:
A Linux Distribution is a precompiled and pre-packaged version of Linux. It may offer certain features and software applications that others do not. There are over 3000 different Linux Distributions. Here are some of the most popular:
4. SUSE (Novell)
7. Slackware (uses stock kernel)
A Linux clone is a Linux version based on a certain distribution. For e.g. Cent OS and White Box Enterprise Linux take the Red Hat Enterprise Linux source and recompile it. This way users get the stability and benefits of the Red Hat Enterprise Linux code but at no cost.
Linux vs Unix:
Linux is Grand Daddy Unix like operating system
Unix is the “original”
Unix is broken down into System V and BSD (Berkeley Software Distribution)
Unix is typically run on larger mini-computers and distributed through commercial
variants like IBM’s AIX and SUN’s Solaris.
However, you can get free UNIX, called FreeBSD.
Linux is made for PCs and lower end servers.
Linux is a type of UNIX.
Comparison of Linux Vs Windows: Windows Strengths
1. Better support
2. More software available
3. Easier for new users to use.
4. Professional & commercial development teams
5. Closed source makes it more secure (debatable) Comparison of Linux Vs Windows: Windows Weaknesses
1. Because of its popularity, it is the target
2. Closed source makes modification difficult
Strengths and Weaknesses of Linux: Linux Strengths
1. Open Source make it more secure (debatable)
2. costs less (free)
3. Most applications are free
4. Highly portable (on cell phones, in cars, etc)
5. Highly customizable
6. The “networking OS”
Strengths and Weaknesses of Linux: Linux Weaknesses
1. Challenging to learn how to use
2. Can be difficult to install applications and patches
3. Devices are not always supported
4. Applications aren’t always available (debatable)