Content storage reveals a fundamental difference between the editors. The classic editor stores content as basic HTML in the database, relying on WordPress’s auto-paragraph functionality.
The block editor stores content as serialized blocks wrapped in HTML comments. This structured format identifies each block type and its attributes, creating a WordPress-specific data format.
This change is permanent and irreversible. Once content is converted to blocks, it’s stored in this new structured format. This enables more sophisticated content management but moves away from generic HTML storage.