What's the point of ODK Collect username/password?

I was just wondering if someone could explain to me the purpose of the username/password feature in ODK Collect? I've set up my Aggregate account and have it hosted on Google App Engine, and I've tried making individual Data Collector accounts for our enumerators. I was testing all of the accounts to make sure that they could access the server, but when I made errors in the username/password, I was still able to access the blank forms. I am assuming this is because there was not an error in my URL, so I am just curious if there is any reason to actually create usernames/passwords for my enumerators since it seems they only need the URL to access blank forms.

Hi @Conor_Gallagher,

Odk software has implemented the username / password to prevent unauthorized access / submission . But admin can configure the software to allow anonymous submission, meaning if someone has the url, can have access to form/ submit data. To disable anonymous access you must uncheck this options in the admin section.

See this image: