If you don’t understand copyright and you consider yourself a professional writer, then you do not understand the business you are in. If you have published a novel, traditionally or indie, and you do not understand copyright, you are volunteering to get screwed over and over and over again. I say this often, and I’m saying it loudly again, because the trend for 2019 and beyond is that every organization you do business with will try to take a piece (if not all) of your copyright on each and every one of your projects.