Opensource.com - https://opensource.com/article/18/1/spdx-clears-confusion-around-software-licenses
Around this time every year, our minds turn to copyright. Or maybe they turn more to copyright. After all, open source works because of copyright law. As you may already know, copyright laws give the authors of works the exclusive right to copy (among other things) their work. These rights attach as soon as the work is fixed in a tangible medium (written down, saved to disk, etc.). So the rights that open source licenses grant rely on copyright law.