The Master database is the heart and soul of SQL Server. It basically records all the system level information. Every instance of SQL Server will have an independent Master database; as it captures instance level configuration information. The information which is captured in the Master database includes SQL Server instance level configurations, linked server configurations, SQL Server Logins, Service Broker Endpoints, System Level Stored Procedures, and System level Functions etc. The system and user databases related information such as name and location for user and system database are captured in Master database.

If master database is corrupted or if it is not available then the SQL Server Service will not start. In SQL Server 2005 and later versions the system objects are stored in Resource Database rather than in Master Database. The Master database is created using Simple Recovery Model.