With retina displays becoming more common and inexpensive, web designers need to accommodate for this rapidly growing new technology.
Retina displays have a pixel density that is so high your eye can’t distinguish individual pixels. This can have a major effect on small images that you put on your website such as icons and logos.
The difference between images that are PNGs and JPGs verses images that are SVG is drastic. SVG images are vectored, which means they are scalable like fonts. Therefore, on retina displays SVGs will not lose their resolution like PNGs and JPGs.
To give your website the highest quality consider using SVG images. Using SVG images will make your site look perfect no matter the size or scale of the image. To continue using PNGs and JPGs because they are familiar would be a mistake. Especially when the quality of your images, and therefore your site, will depreciate.