There are different kinds of uploads and downloads, please find descriptions of what each means below.
Modification Upload : Uploads quantity and price changes only
Product Upload : Adds new products, upload changes to product information, deletes products.
Generate Orders : Makes request to generate the latest order file
Download Orders : Downloads the latest order file available
Order Dispatch Upload : Mark orders as dispatched on marketplace
Order Cancellation Upload : Mark orders as cancelled on marketplace
Order Refund Upload : Mark orders as refunded on marketplace
Generate Open Listings : Makes request to generate an upto date listings report
Download Open Listings : Downloads the latest listings report and used to flag items not on marketplace