I learned that only the copyright owner has the right to their work. All other people must pay for copyright permission. The copyright only lasts for fixed amount of time. Then it goes to public domain. This means that it will be free for anyone. I was surprised that if children want to use someone's work, they just have to do some transformation from the original work.I will have my students will go to my Dropbox to access files that I put in there to supplement lessons. They can use videos in there, share documents, and it can be used as workstations.