Richard Stallman, the initiator of the Free Software movement, published a very easy to understand video message on what software freedom is about.
If you can’t see the video, you can download Richard Stallman’s video message here.
If you wonder why there’s no embedded Flash video version from a site like Youtube, please download the video, watch it and you’ll get your answer. (Although if only I could restrict Youtube to make it webm format only, that might be okay)