A product must be ready for Amazon to allow posting on Amazon. It should also be Amazon Enabled to send the correct inventory quantity.
Post Individually from Amazon Properties page
In Bulk from the Manage Inventory Page
Explanation of the Listing Options
The options above can be grouped to 3 options:
1) Launch to Amazon Catalog from Manage Inventory page and Post to Amazon (Existing Catalog) from Amazon Properties page.
This action will post the items on Amazon but uploaded document will only contain the following minimal information that only affects your product, not the entire listing:
Send the following info:
This action will generate a complete update file. This means that any information included or information not included in the feed may replace or delete product information that has been entered on the listing by other sellers depending on whether you have page detail control. Read more about Page Ownership and Page Detail Controls for Amazon here. It will, however, delete product information in your SellerCentral account that you have may have entered on the product details (for example, if you created the listing through Seller Central and only afterward brought it into SellerCloud).
3) Post to Amazon (Partial Update) sends the following:
This feed is sent with as PartialUpdate which means it only updates the information that is sent. Date which is not included in the feed will not be overwritten (i.e. UPC)
Read for options regarding updating existing products in your Amazon catalog here.