Final answer:
A form of copyright that allows creators to share their work and use others' under varied boundaries is the Creative Commons license, which includes various levels of freedom and protection, such as the Share Alike condition.
Step-by-step explanation:
A form of copyright where content creators can share their work and use others' creations based on varied boundaries is known as a Creative Commons license. This system provides different levels of freedom and protection, with terms such as attribution, non-commercial, no derivatives, and share alike, among others. For instance, a work shared under a Share Alike license allows others to distribute derivative works only under a license identical to the original. Creative Commons licenses support the sharing and use of creativity and knowledge through free legal tools, helping creators to grant copyright permissions in advance to their work.