What does the Importing and Queued status mean?

After creating a new discount set, or adding codes to an existing one, you will see one of the following statuses:

• Importing - The discount set is actively importing the codes into Shopify. You should expect to see the codes available in the Shopify Discounts after the estimated generation time. Note that the generation time is only an estimate and may vary.
• Queued - The discount set is waiting to import the codes into Shopify. You will only see this status if there's already an existing discount set in the Importingstatus. Due to rate limits in Shopify's API, we limit the number of running discount set imports to one per account. This helps to increase the speed at which an individual import will complete. Queued imports will run in the order that they were entered into the queue.