If you really want to know, then you should probably ask your backup software vendor about these folders. If your backup software decided to create these folders, then it apparently needs them for some reason. Who knows what that reason is?
In any case, how do you expect people here to guess the purpose of these folders without even revealing what backup software you are using? And, more importantly, why are you even looking inside those backup folders? The content and format of those folders is internal business of your backup software.