WooCommerce as a vendor is different than WooCommerce as a site.
WooCommerce as a site is when WooCommerce is connected to Spark Shipping as a selling channel and Spark Shipping is used to fulfill orders by pulling the orders from WooCommerce and sending them to your suppliers/vendors, Spark Shipping can also update the inventory in that channel, push listings and update prices.
WooCommerce as a vendor is when you want to connect another WooCommerce store to be used as an inventory feed. Spark Shipping can pull stock quantities from this WooCommerce store and publish those quantities into your site.
To add WooCommerce as a vendor to your site in Spark Shipping, go to Vendors > scroll down to find the list of built-in integrations and find WooCommerce > Add Vendor.
With WooCommerce vendor, Spark Shipping can pull the total inventory quantity for products from all the locations in that WooCommerce store, or can pull inventory from a specific location that you can select from the Options menu.
Please note: WooCommerce as a vendor does not support order processing to WooCommerce- instead, you can set up custom fulfillment method under the advanced tab.
Please note: WooCommerce as a vendor does not pull costs/prices. The sole function of this integration is to pull stock quantities.