Frontend & browser·Loading, assets and the critical path
you listed several image widths and let the browser pick one based on the screen and the layout.
Responsive images
Also calledsrcset, sizes, picture element
Offering multiple sources with `srcset` and `sizes` so the browser downloads an appropriately sized file rather than a desktop image scaled down on a phone. It is usually the largest single byte saving available on a content page. It only works if `sizes` describes the layout accurately: a wrong value makes the browser choose too large or, worse, too small.