Msdb: msdb database is used by SQL Server Agent for scheduling alerts and jobs and by other features such as SQL Server Management Studio, Service Broker and Database Mail. Model: model database is used as a template for all databases created on the instance of SQL Server It includes instance-wide metadata such as logon accounts, endpoints, linked servers, and system configuration settings. Master: master database stores all system level information for an instance of SQL Server.
They are used by SSMS and other SQL Server APIs and tools, so it is not recommended to modify the system databases manually. System databases are created automatically when SQL Server is installed. There are two types of databases in SQL Server: System Database and User Database.
SQL Server Management Studio is widely used to work with a SQL Server database. A login is used to gain access to a SQL Server instance and a database user is used to access a database. SQL Server databases are stored in the file system as files. Each instance of SQL Server can have one or more databases. In SQL Server, a database is made up of a collection of objects like tables, functions, stored procedures, views etc. SQL Server - GRANT/REVOKE Permissions to User.
