Depending on your locale, you will most likely need to rename the address fields presented to users at checkout. By default, we have chosen generic names like zone to refer to geographical regions like state, province, etc. We have made it possible for you to change the names through a simple form in the Checkout settings section. Here you may enable/disable certain fields, rename them, and mark them as required or not required.
Find it by browsing here:
Administer > Store administration > Configuration > Checkout settings > Address fields
We're open to suggestions on where to better place this form!