Lazy Loading
Lazy loading is a technique in which images, videos or other resources are loaded only shortly before they enter the visible area of the screen, instead of loading all of a page's content immediately, which reduces the initial page size and load time.
In practice
Modern browsers support the native HTML attribute `loading="lazy"` for images, with no additional JavaScript library. One caveat: the very first image above the fold should not be lazy loaded, because that can worsen the LCP value.