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:
display-mode is a CSS media feature that selectively applies CSS based on the display mode of the application. This feature corresponds the Web app manifest's display member. Both apply to the top-level browsing context and any child browsing contexts. This query applies regardless of whether a web app manifest is present. Use this query to provide a consistant user experience between launching a site from an URL and lunching it from a desktop icon.