By performing the Destination List query you'll be able to retrieve all the Destinations the Seller configured for a given set of credentials.
Each of the Destinations returned will be complemented with a collection of content and information about the destination, such as its code, its availability: true/false, its destination leaf, and closest destinations... Note that the amount of information and content returned might vary between Sellers.
Please note that the DestinationList Logic works in a way where the highest level (DestinationTree) normally indicates a Country, and the lowest level (DestinationLeaf) normally indicates the cities below this country. Please note that this information can be different depending on the supplier.