BnB are Bread and Butters. They're basically a character's most useful and reliable combos. The combos with the most potential and/or best option for multiple situations. They're what you strive to do most often because they're the most beneficial towards your goal of winning. Typically you use on BnB, but more of them can arise for different situations in which the typical one is not the best option or simply (usually) not applicable.
Does that answer your question?
Does that answer your question?