I am wondering that do we need to create the separate login at SQL SERVER (server) for all the user using the application for the windows authentication?
How do the windows authentication works? I have a apllication and SQL SERVER (SERVER) running on the same machine. Any user from the same domain can access the application. Application is interacting with the DB through Windows Authentication. Now my question is whether do we need to authenticate each user from the domain at the DB level. That is to craete the login id for all the user for windows authentication.
As I understand you, the application is some kind of server application, for instance an ASP.NET solution. Tecnically speaking you do not need to create a login (and user) for each user, it is sufficient that the application's service account has access. Depending on your design specification you might however go for another appoach, where each user authenticates himself with the database. This might be due to security considerations, or a need (or wish) for the ability to easily monitor how many active users there are on the database.