The term ‘translation-ready’ means that the WP theme supports multi languages. Usually, it includes a subfolder (with name ‘langs’ or ‘languages’) with language files.
It’s very easy to change the displayed language of your WP site when its theme is translation-ready:
1. Open wp-config file (it’s placed in the root folder of the site).
and include the preferred language in the second string. For example, if your language is Bulgarian, you should edit the above code in this way:
In this way, you ‘tell’ the WordPress that language of your site is Bulgarian.
2. If your theme support the language set from previous step, you’re lucky and you don’t need to do anything more – your theme file will be displayed translated in your language.
For example, if you set ‘bg_BG’ in wp-config from the previous step and your theme includes file with name ‘bg_BG.po’ or ‘bg_BG.mo’ (usually in theme subfolder ‘langs’ or ‘languages’) then your theme will be automatically translated in Bulgarian.
In case that your WP theme do NOT include language files you’ve already set in the config file, you will have to translate the language file. It can be done easily:
1) Copy-paste some of the existing po files and rename it in the same way as the language you set in the step one, i.e. if you’ve set ‘bg_BG’, then you should name your file bg_BG.po
2) Download Poedit and open your .po file. Using it you can edit the existing lang string values according to your preferred language.
Note: Poedit will save and .mo file. The difference between .po (Portable Object) and .mo (Machine Object) is that the first one is text based and second one is binary. The .mo file can be used faster.