This feature is going to be replaced in the near future. You can read about this planned change here.
Comments are a way to leave a quick message with your thoughts on a blog post or article page.
Article Comments is an extension enabled by default on Fandom. The comments section can be found at the bottom of article pages on most communities. It can be accessed in one click by clicking the "Comments" button. If comments are not available for a content page, you can use the talk page instead, which is located on the "Edit" dropdown. This extension can be disabled by the community's administrators via Wiki Features as desired.