How to do localization of the site using PHP .po & .mo files?

There is a site on Russian language - you need to add the ENGLISH and POLISH languages.
In WordPress worked .po & .mo files, and I know that the same method can be used in-house and website translated, but HOW to DO IT information was not found.

Anyone can suggest, or throw the link to the guide ?

PS - the question already googled, but the answer is still not found
August 23rd 19 at 10:48
1 answer
August 23rd 19 at 10:50

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