10.8.2, yet still shows up in app store?

Hello, I have a question. I am running version 10.8.2 on my mac now, but in the app store it still shows OS X Mountain Lion for 19.99. Is this an add on to OSx Mountain lion or what? I'm confused and I am a new mac user so I was curious.

Did your Mac come pre-installed with Mountain Lion? If it did, the option to buy it will still be available in the App Store. There is no add on to Mountain Lion.

yes. came pre installed.

The version of Mountain Lion installed on a new computer is generally for that computer only. For example I purchased an iMac in June and got the ML free update, however it was for the iMac only. Folk may have more than one computer and need the download.

What Harry said. Also, if Mountain Lion came pre-installed and you wish to download it for another machine, you'll need to pay the $19.99. Subsequent downloads are free.