You are doing the mashing up. Free Software came first. Free Software took over all the corporate server rooms, and so in 1996, they invented Open Source, as a means of acquiring the incredible energy of developer communities while maintaining control of the code. They are not the same, they do not come from the same place, and Open Source lacks all ethics.
Anyways, Blender is Free Software; Free Software is inherent Open Source, but it is Open Source that lacks ethics, and there is a long and concerted effort to mash up the two into a single thing. But Open Source is a corporate delusion, which will let you down sooner or later.
Open Source can become Closed Source. Free Software cannot. Do you see?