I visited the Google Chrome Webstore and I would like to emulate something. When you rollover the possible applications, a gray box rises from the bottom of the image and displays specific information about that particular application. I have no clue what this is called. So, if someone could tell me, I will then be able to Google it and figure out a way to accomplish doing this with HTML, CSS, or JavaScript. Thank you in advance.
Edit: And if you already know of a tutorial, that would be awesome as well.