Lunix is a specific distribution, but I expect that's not what you were asking. There are a number of 'flavors' of Linux, called 'distributions', or 'distros'. Each of them has its own little quirks, from different desktop environments to how much they expect the user to configure. The easiest way to classify distros (at least in my opinion) is by a combination of how much configuration the user does directly versus how much is done automatically and the software available either prepackaged or in the distro's repositories. I think of there being three 'classes' of distros: newbie-friendly, requiring some experience, and requiring a great deal of experience.
The best known distros in each class:
Newbie-friendly:
Ubuntu/Kubuntu/Xubuntu/anything else that ends in Buntu
Some experience recommended:
Debian/non-Ubuntu derivatives thereof
Fedora/most of its derivatives
Lots of experience required:
Gentoo/its derivatives
This has a lot more information than I could ever fit into this post.