Introduction & Basic Concepts of Linux

• What is Linux ?

Linux open source operating system, or Linux OS, developed by Linus Torvalds is a freely distributable, cross platform operating system based  on UNIX that can be installed on PCs, laptops, netbooks, mobile that can be installed on PCs, laptops, netbooks, mobile and tablet devices, video game consoles, servers, supercomputers and more.

The Linux OS is frequently packaged as a Linux distribution for both desktop and server use, and includes the Linux kernel (the core of the operating system) as well as supporting tools and libraries. Popular Linux OS distributions include Debian, Ubuntu, Fedora, Red Hat and openSUSE.

• Linux vs Windows

	Linux	Windows
What is it?	Linux is an example of Open Source software development and Free Operating System (OS).	Windows is the family of operating system (OS) from Microsoft, which is the most famous OS in the world.
User	Everyone. From home users to developers and computer enthusiasts alike.	Everyone. From home users to developers and computer enthusiasts alike.
File system	Ext2, Ext3, Ext4, Jfs, ReiserFS, Xfs, Btrfs, FAT, FAT32, NTFS	FAT, FAT32, NTFS, exFAT
User Experience	Although there are many GUI applications, most of the work is done through Terminal (a console window), and if a problem arrises GUI is rarely usable to fix them.	Everything can be controlled through GUI and incompatibility problems are rare.
Run levels	Multilayed run levels	Single run level (safe mode)

• Difference between Linux and Unix OS 

	Linux	Unix
What it is?	Linux is an example of Open Source software development and Free Operating System (OS).	Unix is an operating system that is very popular in universities, companies, big enterprises etc.
Cost	Linux can be freely distributed, downloaded freely, distributed through magazines, Books etc. There are priced versions for Linux also, but they are normally cheaper than Windows.	Different flavors of Unix have different cost structures according to vendors
Manufacturer	Linux kernel is developed by the community. Linus Torvalds oversees things.	Three bigest distributions are Solaris (Oracle), AIX (IBM) & HP-UX Hewlett Packard. And Apple Makes OSX, an unix based os..
Example	Ubuntu, Fedora, Red Hat, Debian, Archlinux, Android etc.	OS X, Solaris, All Linux

• Advantages of Linux

Cost: The most obvious advantage of using Linux is the fact that it is free to obtain, while Microsoft products are available for a hefty and sometimes recurring fee. Microsoft licenses typically are only allowed to be installed on a single computer, whereas a Linux distribution can be installed on any number of computers, without paying a single dime.

Usage: Linux can be installed on a wide variety of computer hardware, ranging from mobile phones, tablet computers and video game consoles, to mainframes and supercomputers.

Processors: Dozens of different kinds, which is limited in  Windows.

Security: Linux had about 60-100 viruses listed till date. None of them actively spreading nowadays.

Software: Software on Linux tends to be packed with more features and greater usability than software on Windows. Best of all, the vast majority of Linux software is free and open source. Not only are you getting the software for no charge, but you have the option to modify the source code and add more features if you understand the programming language.