Localizing Templates
When developing your storefront application, you can use one template set or use a unique template set for each locale.
When you use one template set, you externalize localizable strings, and translate the strings in resource files. Salesforce recommends this approach as a best practice methodology.
The advantage of using one template set is that templates (which can hold complex logic to visualize dynamic data) don't have to be modified as the storefront is localized. Also, the display logic exists in a single place (the non-language specific template) only. The externalized strings are stored in a simple file format that can be passed to translation service providers. The translation can be integrated back into B2C Commerce simply by copying the translated file into the cartridge, without potentially breaking the logic.