Who is the General User?

When anybody can open and access your database, they are automatically give the name 'General User' in any activity or history logs.

You can add your own Users from the Data menu so each activity is logged against a User you know, rather than everything being logged against the General User.

Once you have added and tested your logins (menu File > Login) then you can enabled the first setting in your Options (menu Tools > Options) which is 'Login Required' which will force every user to login when the database is opened. Without this enabled a login is not required and is optional.