Language Name: Name of the language.
Code: ISO Language code. Must be unique for each language. In most cases 2 symbols value (for example en)
Locale: Locale is used to auto-detect the language a customers browser is using. You can view the different browser codes here. Must be comma separated.
Directory: The exact directory or folder where you uploaded the language files. Should be similar to public_html/storefront/language/languagename.
Sort Order: If your store uses multiple languages, what order the languages are displayed in.