Difference between red & blue buttons

I see 3 sort of buttons, but what is the difference between the red and blou buttons?

Please explain what they mean, why the red are not seen, or where to see them.

Thanx

The red are system items and can not be edited; at least not in the builder.  The green are submenu items and the blue are the top menu items; the blue and green can be edited.

Thanks, but why they need the red ones, where can i see them in the front?
Or are they only in the back of the website? 

No, they show up in the submenu items.  For example, a member's menu bar on their page can be two different ones, one menu for visitors to that page and one menu for the owner of the page.

I don't understand, is there a page where it explain all?
Look at my pic, i see so much red buttons alone.

I don't know how to use them, and if their are ok..

I only know that the submenus not are like i want in the front of my website. 

I am creating a video tutorial that should explain it. I will post a link to the video when i finish it.

Ok. Here is a video i made that should help explain what those red menu builder items are. http://www.deanbassett.com/m/videos/view/Red-Menu-Builder-Items

THIS IS SUPER !!! (thanx Deano)