These options are used every time the list of collections is displayed. This notably includes the navigation bar of the back-office as well as the APIs.
Order blogs by
This where you can change the order at which your blogs will be displayed. You have the option to arrange your blogs by Blog Id (default setting), Name, Short name, Tagline, Description, URL "filename", or just by random order.
This where you can change the direction of the blog list order that you have selected in the Order blogs by field. You have the option to list your blogs in ascending or descending order.