The fetch() method of the GlobalFetch mixin starts the process of fetching a resource. This returns a promise that resolves to the Response object representing the response to your request.
The Request interface of the Fetch API represents a resource request.
The Response interface of the Fetch API represents the response to a request.
The clone() method of the Request interface creates a copy of the current Request object.
The context read-only property of the Request interface contains the context of the Request (e.g., audio, image, iframe). This defines what sort of resource is being fetched.