Closing Orders
Statuses
There is no official "closed" status for orders, but you can consider it closed when it is in either "Returned" or "Returned with Discrepancies" status.
tip
Similarly, once an Invoice is in "Paid", "Void" or "Uncollectible" status, then it is closed or completed.
Archiving
You can't "archive" orders or invoices either, since you'll often need to refer back to them and aggregate them in various reports. Unless you delete an order or invoice, it hangs around for life.