Amazon has two kinds of reports that they send:

Orders

Transactions

 

When the sale occurs, an order is generated.  It has sufficient information to fulfil the order but may not capture all of the expenses.

Typically Amazon creates a settlement notification every two weeks.  In this settlement report there are not only order information but other transactions such as shipping, freight, inventory charges etc.  

We are keen to use the transaction information for accuracy but also want to utilise order information that is more recent than the last settlement.