What is the point of a baking rack? I notice when I bake cookies (usually chocolate chip or peanut butter) the recipe often says "place on baking rack to cool". Because I don't have one, I just place them on a plate after removing them from the pan. It doesn't seem to do any harm. What is the point of buying this special piece of equipment?
A cooling rack serves two primary purposes.

First, it allows the cookies (or other baked good) to cool faster by letting air circulate completely around the cookie.

Second, it prevents the steam escaping from the cookies from soaking the bottoms, and other cookies placed on top.