Copyright is a form of protection given to the authors or creators of "original works of authorship," including literary, dramatic, musical, artistic and other intellectual works. What that means is that, as the author of the work, they alone have the right to do any of the following or to let others do any of the following:
make copies of their work;
distribute copies of their work;
perform your their publicly;
display their work publicly;
make “derivative works” (including making modifications, adaptations or other
new uses of a work, or translating the work to another media).
By getting a child to recognize they have the same rights as does some of the well known authors, musicians, etc they read or listen to will help them understand why copyright is so important for us all.