<p>The difference? Well here it is: A pre-application is used for colleges to prepare for your actual application. They advice you to send the pre-application if you consider applying. The emphasis is on consider. So just because someone sends his pre-application to college XY, it does not mean that he wants to apply for sure. But the 1st part of the CU application is just a normal part of the actual application. Brown has a 2 part application as well. So do all the commonapp colleges. So if you complete and submit a part of the actual application, it is different from sending a pre-application, because you don't just consider applying to that college anymore, you're already applying. </p>
<p>Also, how does the letter you sent prove anything? It says that his application was incomplete not that he got rejected. Also, I still don't understand why you did not call them to cancel the application.</p>