What is the difference between this Portal and the one I used when applying to Arcadia?

They are actually the same portal! 

Once you become an undergraduate student at Arcadia, there are two things that change about the MyKnight Portal; one is the way you access it and the other is the content. 

Though you used to use your personal email address to log in, starting one week prior to your first term at Arcadia, this is no longer the case. The only way to access the MyKnight Portal from that point on is through Portalguard.

And because you are now a matriculated student, the content of the portal changes as well. You now see information that is helpful to navigating your experience at Arcadia.

Please note, if you are an undergraduate student who has applied to a graduate program, you will be able to review information about and the status of your application in the MyKnight Portal as well. To apply, visit the website.