Default language for your CiviCRM instance and where it will be hosted (only US and EU are currently available). Some languages may not be 100% complete and have strings in English. You can see the status of translations on Transifex
. You can help improve translations by creating an account on Transifex. We update the Spark translations once per month. For any questions regarding translation, please join the translation channel
on CiviCRM's chat platform.