An authorization number or transaction ID, which is sometimes referred to as an order number, are all the same thing. Confusing, right? Don't let it be. This simply refers to the 6 digit number you receive when a BizX transaction has been completed. It acts as your receipt for the transaction and when you receive it, you'll know the particular sale has been completed and the funds are now in the seller's account.
When you receive your monthly statement, you'll see every transaction itemized and each one of them will reference the transaction ID or order number.