srcset Attribute specifies an URL to an image along with a width descriptor (positive integer followed by w), or a pixel density descriptor (a number followed by x). It determines the set of images the browser can choose from with each image being a different size. The width or density descriptor is based upon the image’s real size.
srcset Attribute can be used with the following elements:
Further information is coming soon. In the meantime, please read our commentary under the above links.