Hello
Cart attribute: If TRUE it vill be visible in cart and on invoices etc. If FALSE will only be seen in category and Product details. Attribute value can be set by customer (Cart input == TRUE) or by storeadmin (Cart input == FALSE).
Cart input: If TRUE, attribute value can be set by the customer in some way, if FALSE only storeadmin can set the value.
regards
Jörgen @ Kreativ Fotografi