Vendor - A provider of products to you, a seller.
Vendor Catalog - A list of items, SKUs, part numbers, and prices that a given vendor sells.
Purchase Order - A document listing Manufacturer Part Number (MPN), Price, and Quantity that is sent to a vendor. The vendor in turn ships the inventory to the destination warehouse as indicated.
Receiving - The first step in unloading a shipment from a vendor. In it, a seller will confirm that all items are accounted for and in good condition.
Stowing - Taking items that have been received, and putting on to physical shelves of the warehouse. This is where the location of each item is recorded.
Restocking - Moving items from one shelf to another within the same warehouse. Used to organize or condense inventory.
Transfer - Sending inventory from one warehouse you control to another.
Forecasting - Deciding what inventory needs to be ordered from a vendor. The forecast will turn into a Purchase Order, which will be sent to a vendor.
Picking - Going to get the physical items that were ordered, and delivering them to the shipping department.
Replenishment - Sending items from your warehouse to an Amazon FBA warehouse.
Floating Inventory - Inventory that is inside of Listing Mirror, but at neither a final shelf - nor sent off to a customer. Floating inventory provides visibility into where any given item is. At the end of each day, all floating inventory should be in a more permanent resting place.