That means that YOU can write on it, too – by leaving a "comment". At the end of most every article you'll find a tiny little "comment" link. If you click on that link you'll be able to type in a comment for me – and for whomever else comes along afterwards because those comments become part of the article, so to speak - as they can be read by anyone. (So, um, keep 'em clean, of course! LOL)
So why might you want to leave a comment? Well, perhaps something in the article might strike your fancy and you'd like to share your thoughts about it, or another perfect reason to leave a comment would be like at this post – where you can actually leave your guess as to what's in the package!
So go ahead and try it! It would be fun to know someone's out there! (And I sometimes comment back in regards to your comments, too.)