Shopify provides different IDs that form the final order, starting from:

a) orderId - this is the Shopify backend order number. This is Shopify's unique identifier that appears in the admin URL of an order. Example: https://rich-returns.myshopify.com/admin/orders/11122233344455

b) productId - ID of a product that can have multiple variants (see below)

c) variantId - the ID of the given variant of a certain product

d) inventoryItemId - each of the variants can be stocked at a different location, which brings us to this metric