Understanding Menu Structure in Video Manager (VIDEO_TS.IFO)

andy

Now that I've started playing with DVDStripper amp; MenuModder I realized that I don't understand the structure and function principles of the DVD video manager too much. I already learned how to change the First Play Entry with IfoEdit (if I want to start my disc with the movie rather than the menu) but I have no idea how menues are working.
How can I see/change what happens, if I press the Title Menu button or Root Menu button on my player's remote? Since on my last project, where I stripped some parts of the DVD, the menu was no longer working although I left all the part of disc's menu in.

Any help/information is highly appreciated!