The ViewAR JavaScript API lets you access the Scene, Models, Cameras and Tracking Systems functionalities offered by the ViewAR Core from the ViewAR Application. In other words - it serves as an abstraction layer between the HTML UI and the C++ ViewAR Core. It allows you to utilize functionalitites of different services (think - ARKit, ARCore, Placenote, ...) with a unified set of JS commands. What it means, is that no platform-specific or device-specific knowledge is neccessary and that you may seamlessly switch between different technolgies (e.g. tracking systems).