Documentation Level: 
Introduction

There are a few useful modules that can help with creating multilingual sites.

  • Internationalization (aka i18n) - a collection of modules to extend Backdrop core multilingual capabilities and be able to build full-featured multilingual sites. It expands content, taxonomy, menu translation sets; provides field label translation; contact form translation; path "translation" to have different paths as translations of each other; synchronize field values across translated content. Other contributed modules can integrate with i18n hooks to expose other entity types to translation.
  • Views translation - makes additional translation and localization options available to Views. Required if needing to translate Views titles, descriptions, and other Views info.
  • Localization update - helps to keep the translation of Backdrop core and contributed modules up to date with the central Backdrop translation repository at https://localize.backdropcms.org or a custom Localization server.
  • Webform localization - provides multilingual features to Webforms: can translate webform strings and properties, components, emails.