MS SQL Server Authentication
Connect to your database using Windows or MS SQL Server authentication
Windows Authentication Mode
When you connect through a Windows user account, SQL Server validates the account name and password using the Windows principal token in the operating system. This means that your identity is confirmed by Windows. SQL Server does not ask for the password and does not perform the identity validation. Windows Authentication is the default authentication mode, and is more secure than SQL Server Authentication.
SQL Server Authentication Mode
When using SQL Server Authentication, logins are created in SQL Server that are not based on Windows user accounts. Both the user name and the password are created by using SQL Server and stored in SQL Server. While connecting using SQL Server Authentication, you must provide your credentials (login and password) every time. When using SQL Server Authentication, you should set strong passwords for all SQL Server accounts.
Blank Password (not recommended)If you attempt to connect to an instance of MS SQL Server by providing a blank login name, the SQL Server uses the Windows Authentication. Additionally, if you connect to an instance of SQL Server configured for Windows Authentication Mode using a specific login, the login is ignored and the Windows Authentication is used.