I'm not sure what you're asking about. You may want to try and make your question more clear. There's a folder called 'blogs' that you get when you download and unzip b2evolution. That's the folder that contains the whole application, and it's the ony one you need to upload to your server. Is that what you're asking about?

Im asking about the folders that can be created for each blog.
There´s an option in the backoffice that says something like "Url of blog folder" which you specify for each blog.

Do these blog folders have any properties? like, blogger´s images go to his/her specific blog folder when uploaded? can you move their skin files to their folder so they can modify their very own copy of the template? stuff like that....

Ok, I see. No, that setting is just giving the path on the disk to the stub file (if you have one).