Permission Hierarchy
The Database Engine maintains a hierarchical list of entities that can be secured with permissions.
These entities are called securables.
The most important securables are servers and databases, but discrete permissions can be defined at a much more granular level.
In Microsoft SQL Server, the actions of principals on securables are controlled by checking whether the corresponding permissions have been granted to them.
The following diagram shows the relationships between the Database Engine permission hierarchies.
An overview of all Database Engine permissions in PDF poster format can be found at