The document discusses next-generation image formats for the internet. It focuses on JPEG XL, a new image format currently being standardized that aims to replace JPEG, PNG, and GIF. JPEG XL provides state-of-the-art compression, supports high bit depths, alpha channels, animation and is designed to be responsive by encoding images into a single file at multiple quality levels. It is also intended to be legacy-friendly by never producing larger files than the original formats and avoiding additional quality loss for existing images.