The link says
The database project now includes the concept of database reference. A database reference is simply a pointer to a database. Whenever you create a database reference, the database project immediately checks the list of database connections in Server Explorer and if there is no connection to that database, it creates such a connection for you automatically. A database reference differs from a database connection, because a reference is merely a pointer; it does not allow you to enumerate the contents of the database. A database connection, on the other hand, lets you inspect the contents of the database.
A database reference is persisted with the database project. When you save a project to disk, the reference is saved. When another user opens the project and begins using it, the reference is available to that user. Furthermore, when any user opens a database project, the project checks that user's Server Explorer for a corresponding connection and if no such connection exists, the database project automatically creates it. "
i.e. a new concept of Database Reference is introduced which is a pointer to a database.
So answer to the question should be "Database Reference".