The document discusses internationalization (i18n) and localization (l10n) for software applications. It explains common i18n functions and files like gettext POT, PO, and MO files. It also provides examples of how to implement i18n in WordPress themes and plugins, including generating POT files and setting the text domain. The overall message is a recap of the steps to internationalize code, which are to read strings, add context and comments as needed, set the text domain, and generate a POT file.