Security is the protection of information through some principals.
- Authentication is the process of logging on to SQL Server by which a principal requests access by submitting credentials that the server evaluates. Authentication establishes the identity of the user or process being authenticated.
Authentication means “who you are”.
- Authorization is the process of determining which securable resources a principal can access, and which operations are allowed for those resources.
Authorization means “what you can do”.
In SQL Server supports four types security levels.
- Windows level security.
- SQL Server Instance level security.
- Database level security.
- Schema level Security.
To get more information about SQL Server Security Mechanism, download the below link.