I recently wrote a post for the iWeb blog showing how and when to use the Picture element and the Srcset attribute.
Images are a massive part of the internet. Traditionally adding images to a web page was simple. We would use the image element and set a source, height and width. It would then display at those sizes, regardless of the device or screen size you were displaying it on.
In 2011 responsive web design started to become mainstream. Responsive web design allows people to receive an optimised browsing experience, regardless of screen size and device. This means we can no longer dictate the size of an image but instead, we must allow it to resize to fit the available space on the screen.
Read the article in its entirety on iWeb’s site.