Understanding copyright and licensing is fundamental to the work of professional photographers, mainly because it is how we create value for ourselves and our work in the long term. Ensuring that the copyright to your work is in fact in your hands, in contractual agreements may create you an income stream in decades to come, particularly for work of enduring significance. Of course, good business practice nowadays, in the World of the internet and social media, often means it is wise, as Jesus said, to “give and you will receive”. So Creative Commons licenses become an important mechanism for you to determine the conditions under which you give. But all of that presupposes that the creative work belongs to you. You need to have ownership before you can give. And that is where copyright comes in.
I trust this article on the Shutha site is useful to you in helping you to grasp something of the history and “heart” behind copyright and why it exists: Copyright and Licensing