Robocopy script help

I made a batch file that uses robocopy to manage my backups for me and it's been a handy little tool but I want to be sure it has access to all the files I want to copy.

 

My question is:

Do I need to worry about using the /B parameter if I'm only working with my downloads, documents, music/pics/videos folders?

 

When I add backup mode it breaks my script and before I go and change everything I want to be sure I'm not wasting my time on something unnecessary. There's very little documentation about what backup mode really does.