Creating External Customer Portal

Hello I am new to Sitefinity and I have been tasked with creating an external portal where we can store clients project folders and documents. The idea is to put each customers documents out there for them to see anytime but the customer can only see their specific documents and no one else. I was told maybe this would be possible using roles. Any assistance with this would be greatly appreciated.

I mean you could permission to the user if you wanted.  I can't see roles making sense because then you could see other peoples documents if they have that role too.

Thanks for your reply! I will definitely look further into it. Any advice regarding setting up an external portal?