Finally closed and cancelled

[surya]

what is the difference between Finally closed and cancelled controls on Purchase order or release

surya

[merlinrajesh]

<u><b>Cancel</b></u>
Purchasing lets you terminate an existing commitment to buy from a supplier by canceling document headers, lines, shipments, or releases. When you cancel a purchase order entity, you are unable to receive or pay for cancelled items and services, however, you can pay for all previously received orders. You also cannot modify a cancelled entity or its components.

<u><b>Final Close </b> </u>
Prevent modifications to or actions against completed documents, lines, and shipments by final closing them. Final-closed documents are not accessible in the corresponding entry forms, and you cannot perform the following actions against final-closed entities: Receive, Transfer, Inspect, Deliver, Correct receipt quantities, Invoice, Return to supplier, or Return to receiving.
You can approve documents that include final-closed entities, but you cannot approve documents that are final closed at the header level. You can print final-closed documents. Finally, you can Purge documents that were final closed at the header level before the Last Activity Date that you specify when you submit Purge.

[macromedia]

How to do PURGING for Cancel and Finally Closed document? (including PR and PO). any request that we can run, or this is technical matter on DBA scripts?
thank you