One of the challenges involved in moving/copying databases to a new location (prior to SQL Server 2012) was copying the dependencies along with the database. External dependencies such as login names, linked servers etc are not automatically copied to the new location when you restore a regular database backup.
SQL Server 2012 (Denali) introduces Contained Databases, a new feature that allows you to embed all the dependencies right into your database. When the database is moved/copied to a new location, all the dependencies are also moved/copied along with the database.