A dictionary for one language: the English strings of the interface (and of your blocks) mapped to their translation.

The library ships Spanish, Portuguese, German, French, Italian and Japanese. Your app adds its own with modules like this one, usually generated by mix elementorex.gen.locale:

defmodule MyAppWeb.ElementorexLocales.Pt do
  use ElementorexCms.I18n.Locale, locale: "pt", name: "Português"

  @impl true
  def dictionary do
    %{
      "Pricing" => "Preços",
      # nil (or a missing key) falls back to the built-in translation,
      # then to English
      "Most popular" => nil
    }
  end
end

config :elementorex_cms, locales: [MyAppWeb.ElementorexLocales.Pt]

A module for a locale the library already ships is merged on top of the built-in dictionary (its entries win); a module for a new locale ("ko", "nl"…) makes that language available.