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.
The credentials read-only property of the Request interface indicates whether the user agent should send cookies from the other domain in the case of cross-origin requests. This is similar to XHR’s withCredentials flag, but with three available values (instead of two):
The mode read-only property of the Request interface contains the mode of the request (e.g., cors, no-cors, cors-with-forced-preflight, same-origin, or navigate.) This is used to determine if cross-origin requests lead to valid responses, and which properties of the response are readable:
The referrer read-only property of the Request interface is set by the user agent to be the referrer of the Request. (e.g., about:client, no-referrer, or a URL.)
The ok read-only property of the Response interface contains a boolean stating whether the response was successful (status in the range 200-299) or not.