@dave “Block-based” WordPress themes are written with HTML templates peppered with dense WP comment markup that makes them reusable components of a WYSIWYG site editor experience.Every part of the site is a “block” that the user can stick anywhere on any page they want.This makes “full-site editing” possible without any programming, although writing these blocks is (I’ve found) quite difficult.(I’m sure this isn’t the full story and I may have gotten some details slightly wrong.)