Most themes and plugins automatically recognize the language version of your WordPress installation and the country you work from. Then they install the right language package and without ever noticing the different language versions, everything is shown in the right language.
But what if a different language then automatically detected is needed? Or what if the right package didn’t get installed, or isn’t even available? Then, custom translations are needed.
As many themes support multilanguage plugins, they have special files signifying each language and their translation from the original encoded words, the .po-files. po stands for portable objects, which work with translations using Gettext for localization. This Gettext is an widely used standard, which is also used for WordPress projects. If there is at least one language file in a .po and .mo version available for the theme or plugin that needs translations, then the easiest way to get results is using a .po editor like Poedit.
When installed, the language files have to be downloaded via FTP and the .po file can be opened in Poedit. The program then shows a list of all the defined words and statements, that can appear on the website in a table. Next to these, there is an empty column, which will hold the translations. So now, one can either translate every entry in the table, or, if only a few changes are needed, search for the words and add the translation. When finished, the new table has to be safed with the old name followed by the language code in small_capital letters. For example: “name-de-DE”. Poedit will automatically create the necessary .po and .mo files. They can now me uploaded into the same folder the original file is in.
When everything is in place, WordPress automatically uses the file with the language code that fits the installation and language settings.