"Product Active" defines whether a product is available for the picking process or not. For example, seasonal products, raw materials or other goods that should not currently to be sent out can be deactivated. In this case, the storage is still occupied, but the products cannot be released for picking.
Please note that marking products as active has no direct connection to the settings in your online shop; it only affects the handling in the warehouse. In order to avoid error messages when releasing the shipments for fulfillment, please make sure that all products for sale in your shop are set to active.