Within Inventory > Inventory Management > Product Details , there are multiple SKU fields. Here is what each of those fields can be used for:
SKU Number: This is known as Stock Keeping Unit. Within ecomdash, this is what we use to match products with in ecomdash and on your storefront, and how we send out quantity syncs and listing revisions.
Supplier SKU: If you supplier uses a different SKU for the product, you can put that SKU in this field. Having the supplier SKU filled out will be useful for creating Purchase Orders for that product.
Warehouse SKU: This is the SKU Number for the product when stored in a specific warehouse. In ecomdash, this is set as your Product SKU by default, but this can be changed. If your supplier uses a different SKU in an Inventory feed, or multiple suppliers provide the same product using different SKUs, then you can use the warehouse SKU to match the SKU used by the supplier in the inventory feed.