Linux is a free Operating
System. Often explained as being free in the sense of freedom, it is
usually free in the monetary sense as well.
Linux is a different way of doing things. It does not use microsoft
code, and there is absolutely nothing illegal involved. It is simply a
competitor to Windows®, built around an open model, where
people share their code to build a better system together.
As a result, Linux is extremely reliable, and much more secure than
Windows or other propeitary (non-open) operating systems. It will do almost everything windows will, usually without the cost.
And even if you think Windows is okay for your needs there are
reasons to switch other than these.
The one downside to Linux is that it can not run Windows programs, but
there are some exceptions. Also, Windows and Linux can be stored on the
same machine, with a chioce given at startup. It is even possible to
launch Windows from within Linux, using virtulisation such as
QEMU.
To find out more about the advantages of Linux, see
this site.
