If you have ever played a PSP, it is the navigation menu. They use it on the PS3 and also some SONY TV's.
Click for an image: (Too big to post, didn't feel like re-hosting it)
http://cache.kotaku.com/assets/resou...xmb_manual.jpg
Basically, you "scroll" right and left to such items as video, music, settings, etc. Then you "scroll" up and down to pick each item under the main one. For example: You scroll to Settings, you then scrool up and down and you will see things like network settings, sounds settings, etc.
I hope that explains it, I struggled to even form that bit of jibberish.