Linux

I know...
I've never heard anything about this.

I what to know...
-What is it?
-What is is used for?
-How can I relate to it? Can  it help me? Can it harm me?

Links...
- http://computer.howstuffworks.com/question246.htm
-http://whatislinux.org/
-http://www.whylinuxisbetter.net/

What I learned...
-Linux is an operating system such as Windows and Mac OS.
-Some how similar to the UNIX operating system
-The creation of Linux started with a desire of simpler, quicker and more powerful computers. Old day computers were huge and cumbersome and standard users were not able to use them.
-It took a while for home users to start using Linux. Programmers used Linux because it was the finest running system ever.
-One of the problems that Linux users have is that this operating system is that it's not compatible with computer software such as Windows.
-Linux provides many applications you can download, many for free.
-Linux is virus free because it uses smart authorization management.
-Linux can provide 4 screens in the same computer.
-Linux can be downloaded form the  internet. This helps the environment as it requires no packaging.
-Linux will maintain the same speed it had since the beginning.
-This program is very simple to use and a discussion board in the Linux website can provide you the answers to additional questions you can have.
-You can install Linux ans still keep Windows.
-This is how a Linux screen would look like even though you can personalize it.

How can it relate to me...

Linux is just another operating system as the one we use every day. I can benefit from it because it is completely free and allows me to do almost anything I want with it. It doesn't risk my security and it gives  me tons of free applications. Linux can make my computer life easier. With Linux I don't have to worry about re-installing it and my computer will always remain fast.

I still want to learn....
How popular is Linux today? Is it still so unknown?