The Window.navigator read-only property returns a reference to the Navigator object, which can be queried for information about the application running the script.
The Web Performance API allows web pages access to certain functions for measuring the performance of web pages and web applications, including the Navigation Timing API and high-resolution time data.
The Window.onunhandledrejection property is an event handler for processing unhandledrejection events, which are raised for unhandled Promise rejections.