Orm is clearly designed to abstract entities from database implementation; Orm separates your model into three basic layers:
Entities are data crates, hold your data, validate values and provide API for value encapsulation, e.g. for relationships.
Repositories form a layer which takes care about your entities. Repositories manage entities and provide an API for their retrieving, filtering and persisting.
All layers are connected in the central Model class. Each entity must have defined its own repository and mapper.