What is the difference among base_grand_total , grand_total, sub_total in Magento CE 1.7?

Question

Can anybody provide a clear definitions for the followings in magento?

grand_total
sub_grand_total
sub_total

Any help will be appreciated.

Answer 1

base_grand_total is the base currency total for the order grand_total will be the grand total of the currency used to checkout.

Example of this would be

USD and GBP

The store currency is GBP

base_grand_total = 10.00 in GBP

Customer checks out in USD

grand_total is 15.00

sub_total is pre-tax.

Answer 2

base_grand_total is in base currency

grand_total is in the currency of the website where the order was placed