Definition of Free Software (Laut FSF)

A program is free software if you as the user have
the four essential freedoms. The freedom to:

- run the program as you wish, for any purpose.
- study how the program works, and change it so it does
  your computing as you wish.
  Access to the source code is a precondition for this.
- redistribute copies so you can help your neighbor.
- to distribute copies of your modified versions to others.

"A program is free software if it gives users adequately
all of these freedoms. Otherwise, it is nonfree. While we
can distinguish various nonfree distribution schemes in
terms of how far they fall short of being free, we consider
them all equally unethical."
https://www.gnu.org/philosophy/free-sw.html