The booking engine currently allows guests to book in more than 20 different languages. You can choose which languages you would like to support here: Settings -> Languages & texts -> Language Support. After selecting which languages to support, you will also need to enter translations of the names and descriptions for your room types and extras.
Even if you only would support English and perhaps one or two other languages, the booking engine can still support more languages. For example, a Chinese guest could get all help texts and dialogs in Chinese, only that the room types and extras would be displayed in English. The booking engine will auto-detect the guest’s preferred language via the browser, and automatically display the correct language, if that language is supported.