What is Sitecore Media Library
Sitecore Experience Platform allows you to manage content, engage in digital marketing, and analyze and report on the results.
You can manage all your media items from your Media Library, such as images that you wish to embed in a web page or make available for download by visitors. You can find all your media items in the Media Library, including images, documents, videos, and audio files.
Media library users have access to all their media files in a structure similar to content trees. They can browse the tree or search Sitecore's search functionality to locate media content items, upload them, and version each media item.
By default, the media library does not support modern image formats such as WebP, AVIF, or JPEG XL. Dianoga is an extension that provides a solution. The automated image optimizer is integrated into the Sitecore media library. You may reduce your images served from Sitecore by 8-70% automatically. Dianoga automatically performs its optimization after images are placed in the Sitecore media cache, so it will not adversely affect your site's performance. With Dianoga, your site will serve fully optimized media library images, even if you use Sitecore's dynamic resizing functionality. Whether you have optimized every photo uploaded to the media library before after Sitecore performs image processing, the resulting image will not be optimized. In addition, Dianoga is great for situations where content editors may not be image editing experts and upload pictures with lots of EXIF data or other unnecessary metadata - these are automatically removed before the image is displayed.
Dianoga supports WebP and has a Github issue regarding AVIF. However, they have decided not to support AVIF as they believe that JPEG XL will be more widely accepted in the future.