The Microsoft Text Translation API is a powerful tool for adding translation capabilities to web applications. It offers a text-to-speech endpoint that returns an audio file of the submitted text, allowing users to hear the translated text spoken by a native speaker in their preferred language. The API can be used with JavaScript and other programming languages to translate text into 80 different languages. To use the API, developers must first subscribe to it through RapidAPI and create an account. They then need to clone the starting repository from GitHub, install dependencies, and start the app. Next, they need to explore the Microsoft Text Translation API dashboard, add API calls, and set up language options. The API can be used to translate text into a target language, retrieve speech recordings for translated phrases, and display translation capabilities in web applications. By following this tutorial, developers can add translation capabilities to their web applications using the Microsoft Text Translation API.