They are identical Progressive enhancement removes features Progressive enhancement starts with a working basic version and adds features for capable browsers; graceful degradation starts full-featured and provides fallbacks for older browsers Graceful degradation requires no fallbacks
To reduce file size by removing whitespace and comments and shortening names, which speeds up downloads To encrypt the code To add browser compatibility To make the code more readable
ARIA is required for SEO Use a native HTML element with the required semantics (such as <button>) instead of adding ARIA to a generic element, wherever possible Add ARIA roles to every element ARIA replaces HTML
