Using URLs also helps instructors avoid copyright issues. Some courses attempt to bring the entire class together in a chat room for real-time discussions. A good writing course should ask you to write. One of the advantages of learning online is the ease with which you can submit your homework to the instructor, and have it evaluated and returned. Website, others deliver them by e-mail.
Some courses also ask students to post or share their homework assignments for class critiquing.
If you raise a question that would benefit the rest of the class, the instructor may ask your permission to share the question and answer in the public discussion. If you're looking for a course on screenwriting, for example, don't just jump at the first screenwriting course you see. Make sure the course is matches your level of expertise. Since online education greatly facilitates personal feedback, it seems almost pointless to take a writing course that doesn't provide writing assignments. Again, review the syllabus carefully-and find out if you can review sample lectures or assignments from previous classes.