Authentication

Microsoft SQL Server authenticates users with individual login account and password combinations. After the user’s identity is authenticated, if authentication is successful, the user is allowed to connect to a SQL Server instance. There are two types of authentication:

• Windows authentication
  Uers must connect to the SQL Server using a Windows user account (a Windows login ID and password that is provided during the Windows login session).

• SQL Server authentication
  Users must connect to the SQL Server using SQL Server login account (a SQL Server login ID and password).

SQL Server can operate in one of two security modes, which control the type of accounts that must be used for access to the server:

• Windows authentication mode
  The SQL Server only uses Windows authentication.

• Mixed mode
  The SQL Server uses both Windows authentication and SQL Server authentication. When connecting, users can choose to log in with a Windows user account or a SQL Server login.

  Important: SQL Server authentication is provided for backward compatibility only. For improved security, we recommend that you use Windows authentication.

For more information about authentication, see your Microsoft SQL Server documentation.