Classic Themes, Child Themes and Hybrid Themes

A classic theme is a traditional (non-block) WordPress theme that does not support full site editing. You can use the WordPress Theme Customizer to edit a classic theme and control the appearance of your website.Classic themes are built using PHP templates and use stylesheets and HTML files to control a website’s appearance. They are different from the latest block-based themes since they have fixed layouts and designs.

Child themes are extensions of a parent theme. They allow you to modify an existing theme without directly editing that theme’s code. They are often something as simple as a few minor color changes, but they can also be complex and include custom overrides of the parent theme.

A hybrid theme combines modern block theming with classic PHP templates. This makes for a smooth transition from classic to block themes. It uses theme.json to define styles and customize the block editor while also using traditional PHP template files and leverage the block editor for content but not for building the theme itself.