API - Wikipedia
https://en.wikipedia.org/wiki/API
An application programming interface (API), is a computing interface that defines interactions between multiple software intermediaries.
Translate API — Yandex Technologies
https://yandex.com/dev/translate/
The API provides access to the Yandex online machine translation service. The API makes it possible to embed Yandex.Translate in a mobile app or web service for end users.