Login for users without Mendix predefined login screen?

I have gone quite far with my app ,having custom login implemented (as Alternative homepage for anon. users) but now I found out - when I switch to Product security, Mendix login screen appears. What is the purpose of login widget then? Or is that correct to define anonymous users to login through my form (do they become users when logged in?) E.g. I want users to be able to register but I cannot edit the Mendix login form (when I set Production). Maybe I dont understand users in Mendix's context? I believe all apps will eventually go to Prod and how new users could register?
1 answers

You could use the login widget on a form which is accessible for anonymous users. On this same form you could offer anonymous users the option to register to your application.

Edit after comment:

You can find documentation about security in Mendix here and here. Maybe that helps you understand the way Mendix handles security.