Translation files are automatically downloaded and imported when languages are added, or when modules or themes are installed.
This page allows translators to manually import translated strings contained in a Gettext Portable Object (.po) file. Manual import may be used for customized translations or for the translation of custom modules and themes. To customize translations you can download a translation file from the Drupal translation server or export translations from the site, customize the translations using a Gettext translation editor, and import the result using this page.
Note that importing large .po files may take several minutes.