So I've ordered my first Mac, and I've always been a windows user. I see people talking about OS versions, is the version something similar to the SP for windows? Is Snow Lepoard that I see people talking about a new OS or an upgrade for the current OS or....? Sorry if the question seems noobish, I'm just used to WinXP just downloading SP as they come out, and I'm not sure about how the Mac OS works, will it just update the version as neccesary, will I need to purchase it, or simply visit a site? Thanks a bunch!