Thanks James. Publications are simply organizations and entities who accept submissions from, as well as publish posts from a wide variety of writers. Most have a general theme or topics they typically try and follow. The advantages of doing so are in the fact many have thousands, if not hundreds of thousands of followers. So your work is getting that much more exposure when they accept and publish it. You’ll get the hang of it if you stick around for a bit. You can apply to be a writer for most of the major publications on Medium through a site called www.smedian.com
Thanks again for reading.