what is priority transfer?

<p>Some of the schools I'm applying for have "priority transfer" systems, and it seems their deadlines come quicker than the normal deadline(mostly 3/15 for me).</p>

<p>Can anyone tell me the difference between the two, or by when should I submit my applications? </p>

<p>(Majoring in biz&econ, I'm applying to Upenn, NYU and Cornell, Brown, U of Chicago and Michigan.)</p>