An Signed Exchanges (SXG) is a delivery mechanism that makes it possible to authenticate the origin of a resource independently of how it was delivered.
Enabling Signed Exchanges can help speed up web page performance and thereby impact your site’s Core Web Vitals, in Particular Largest Contentful Paint (LCP). As an early adopter, Google Search uses SXG to provide users with a faster page load experience for pages loaded from the search results page.
Signed Exchanges (SXGs) (web.dev)
Enabling Signed Exchanges can help speed up web page performance and thereby impact your site’s Core Web Vitals, in Particular Largest Contentful Paint (LCP). As an early adopter, Google Search uses SXG to provide users with a faster page load experience for pages loaded from the search results page.
Signed Exchanges (SXGs) (web.dev)