The lifetime of a transaction is defined by its status. The below outlines each status an order can have:

 

Pending - Order has been submitted and not yet acknowledged by the seller.
Updated - Items have been added to or removed from the order.
Processing - Order has been acknowledged by the seller but not yet ready to be invoiced.
Ready - Items in order verified, shipping or any additional costs added. Seller sends an Invoice to the buyer.
  Paid- Payment received.
  Packed - Package has been sealed but not yet shipped.
  Shipped - Package has been shipped but not yet received by buyer.
  Received - Package has been received but the buyer has not yet verified the contents on the package.
Completed - Package received, contents verified, the order is completed.

 



https://www.bricklink.com/help.asp?helpID=41