The cancelled tab contains a list of all the orders that have been cancelled using Webgility.
Three things to keep in mind regarding cancelled view:
No functions can be performed on cancelled orders. If you need them to be re-instated you will need to make a new order in the online store and download it into Webgility.
Just because an order can be cancelled within Webgility does not mean the customer is refunded their payment. After cancelling an order you will want to check in your online store to see if the order was cancelled and refunded there as well.
You can move orders from Cancelled view to the trash by clicking the trash can icon when you hover over the order.