Dear teachers,

Would you tell me your opinion concerning the interpretation of the expression in bold in the following sentence?

You may get these books by money order.

order = a commercial document used to request someone to supply something in return for payment and providing specifications and quantities

money order = an order for the payment of a specified amount of money, usually issued and payable at a bank or post office

purchase order = a document containing a formal offer from an intending buyer to buy from a supplier the goods listed, in the quantities and at the approximate prices stated in the order

Could you tell me the difference between “money order” and “purchase order”?

In my native 1200 years “old” language we use for that purpose the term “pay order” which we hand in the cash counter.

Thanks for your efforts.