Most of you must be wondering why the order item values has so many “repeated” fields like the following:
While you also have the following
You might be having a single website using a single currency and for each item your orders have you will se the exact same values. But the thing changes when you store(s) handles several currencies.
For instance, if you have a store that accepts US Dollars and Euro, but your default currency is USD, the base fields will be expressed on the default currency, while the other will be on the currency of the store the order was purchased.
This a very common question on the day to day or even something you need to know if you are going to take the Magento certification.