When you developing WordPress themes and plugins, you should have international users in mind. By doing so, you can help people translate your work into other languages. This is known as internationalization in WordPress.
And the process of translating an internationalized theme or plugin to another language is known as localization.
By internationalizing your theme or plugin, you are making way for other people who are proficient in other languages to translate your plugin into their language. This allows your code to be used by people who rely on those languages to manage their WordPress sites. You can read more about it from the below resources –