Master Database:
- It is a system database which contains server’s configuration.
- Used for Backup for master database.
- SQL Server can't be started without it.
Msdb Database: Stores information regarding,
- Database backups.
- Agent information,
- DTS packages,
- SQL Server jobs,
- Replication information such as for log shipping.
Temp Database:
- Temp Database holds temporary objects such as global temporary tables, local temporary tables and temporary stored procedure.
- It stores version information.
- This is a temporary database used to store temporary, tables, cursors, indexes, variables etc.
- Temp Database is re-created every time SQL Server is started.
- Auto shrink is not allowed for temp Database.
Model database
It is a Template database used in the creation of a new database
Resoure Database
- Resource Database is a read-only database.
- It contains all the system objects that are included with SQL Server.
- The Resource database does not contain user data or user metadata.
Other Related Database of Sql Server Distribution, ReportServer and ReportServerTempDB
Distribution: Used for SQL Server replication only.
ReportServer: To store metadata and other object definitions.
ReportServerTempDB: Acts as a temporary storage for reporting services.