"Its an ORMapper where you define entity types as abstract classes and the Library implements those classes and implement INotifyPropertyChanged. It also gives you IQueryables with INotifyCollectionChanged implemented, which gets updated when an Entity is created or has changed so that it meets the where expressions of that Queryable and fires the according events. Furter more it doesn't have something like a DBContext, all objects are int something like a "Aether" holding the entity instances. So when you have a currencies table in your DataBase with a USD entry in it, then you have only one Instance of that USD entity in your "Aether". You can use that instance to assign it to Entities with a foreign key referencing it, or us it to compare, enumerate, etc..."