resource database contains all the system objects deployed with SQL Server 2012. These system objects include the system stored procedures and system views that logically appear in each database but are physically stored in the
resource database. Microsoft moved all the system objects to the
resource database to simplify the upgrade process. When a new release of the software is made available, upgrading the system objects is accomplished by simply copying the single
resource database file to the local server. Similarly, rolling back an upgrade only requires overwriting the current version of the
resource database with the older version.
You do not see the
resource database in the list of system databases shown in SQL ...