It's built on the concept of software freedom. The idea is that, whether the software is free or purchased, the user has the right to share, customize or otherwise improve upon it, without penalty, guilty feelings or harsh words. This is true for all software covered under the GNU Public License . A Little History Linux gets it's name from Linus Torvalds, who wrote the first Linux kernel while attending the University of Helsinki. The Open Source and GNU Project promote freedom of software.
Most people mistake 'freedom' for 'free'.
There is a striking resemblance. But the idea is to set up an idea and software sharing community. What is free is the right to change and share software. Companies are encouraged to sell software to the Linux community, but it had better work, and work well, because there is sure to be a comparable GNU version that cost zilch. GNU's not Unix.