Importing allows you to bring your existing items onto Vendoo from one of the marketplaces, so that you can easily crosspost them to the other sites.
The Delist/Relist feature is a way to remove a listing from a marketplace and then post it as a new listing. In addition to refreshing old inventory, this feature also allows you to automatically delist your sold items.
The All Marketplaces add-on allows you to list your item on all available marketplaces on Vendoo.