Richard, et al,
Pls forgive the nuisance question here and my confusion.  I had a question after my last lesson (Expert 9).  I was asking about linking primary and foreign keys. To lighten his burden, I'm posting my question here.

I understand 1) Primary Key must be an Autonumber. 2) Foreign Key must also be a number (long integer) usually with the same name to form a relationship.  For example, as Richard says, "If you're doing customers and orders, the CustomerID is the primary key in the customer table."  
NO ISSUES THERE.  I get that part.  It's potentially the second half of the equation where I have questions, if applicable.  Here's where I'm unsure.  (I even went back and listened to Expert 2.2. again, where he introduced explicit/global relationships (of the one-to-many variety), to try to clarify things in my own head.)  
My question: Must you ALSO enter the OrderID in CustomerT (i.e., the opposite direction, as a foreign key)? In other words, do BOTH TABLES require foreign keys AND primary keys from each corresponding table?  If so, this would mean CustomerT would have BOTH CustomerID (primary key) and OrderID (foreign key), while OrderT would have OrderID (primary key) and CustomerID (foreign key).  
Based on my review of your simple tables in Expert 2.2 today, it appears not.  
Please confirm.
v/r