Importing localization packs
This section provides you with an extensive list of existing localization packs which you can import. Not only does it set your PrestaShop install with your proper local units, but it also adds a lot of other data:
States. When shipping product to a country, knowing which state it is sent to can prove important, as this might have an impact on local customs and taxes. The added states can be viewed and edited in the "States" page under the "Localization" menu.
Taxes. The real importance of localization is local taxes, and they can be numerous and varied depending on the country or the state. PrestaShop provides you with a basic support for the major taxes and tax rules. The added taxes and tax rules can be viewed and edited in the "Tax" and "Tax rules" pages under the "Localization" menu.
Currencies. Foreign customers will appreciate being able to convert the prices on your shop into their own currency. You should at least have US dollars and Euros available along of your country's own currency (if not one of those two). Once added, you must activate a new currency using the "Currencies" page under the "Localization" menu, and make sure the conversion rate is correct. The added currencies can be viewed and edited in that "Currencies" page.
Languages. All the public fields on your shop can be created in multiple languages, and it is important you do so for your product's name and description, at the very least. Note that importing a language also imports its date format (d/m/Y, m/d/Y, d.m.Y, etc.), among other things. The added languages can be viewed and edited in that "Languages" page under the "Localization" menu.
Units. Weight, dimension, volume, distance: these units are essential in order to correctly describe a product to your customer, and for your own packaging information. They can be viewed and edited on this very page, in the "Localization" section.
Change the behavior of the taxes display for the groups. This is not data to import but a setting that you can change when doing the importation.
As you can see, this additional data is optional: you can choose to import the currency and language for a given country, and not its taxes, for instance.
While you should not add too much local data for fear of overwhelming both yourself and your customers with it, it may be useful to import the localization pack for your most visited countries (according to your stats).
Apart from the default units, you cannot automatically remove all the data for a given country; if you need to remove data, you will have to do so manually, in their respective pages under the "Localization" menu.