I think it means, you have to bring your product to VendorCentral from the SellerCentral/MarketPlace,

VendorCentral is where you become a Vendor/Distributor to Amazon, i.e, Amazon should be allowed to purchase at wholesale price from you, and sell it themselves.

and MarketPlace/SellerCentral is where you can sell directly to customers.

Vendor Central which is structured differently than Seller Central