Block vs Classic Themes
How Block Themes and Classic Themes Define Layout
A block theme vs classic theme comparison is really a question about where a site's layout is defined. A block theme defines it with blocks inside editable templates, while a classic theme defines it in template files that developers edit directly.
A theme controls the look of a WordPress site. In a classic theme, files such as header.php and single.php contain the markup for each part of a page, mixed with PHP, the server-side programming language WordPress is built with. Changing the header or the layout of a post usually means editing those files or using the options the theme provides.
A block theme stores its templates as HTML files containing block markup. A theme.json file holds global settings such as colours, fonts and spacing. The same block editor used for writing posts is then used to edit headers, footers and templates.
What Full Site Editing Changes for Site Owners
Full site editing, often shortened to FSE, means editing the whole site inside the block editor, not just the content. With a block theme, the site editor lets you change the header, footer, navigation and templates visually and preview the results before publishing.
With a classic theme, the same parts are usually changed through the Customizer, widget areas or theme options, or by editing code. Those tools still work and are useful, but they offer fewer places to control the layout, and they do not always share one editing experience.
Example: A Bakery Updating Its Opening Hours
A bakery owner wants to change the opening hours in the footer and add a seasonal banner to the homepage. Her site uses a block theme, so she opens the site editor, edits the footer and adds a banner pattern. The change takes a few minutes and needs no code.
Her neighbour runs a classic theme whose footer was built in template code. A small change there means editing a template file or relying on a widget area the theme happens to offer. If he cannot make the change himself, a developer is needed, which adds time and cost.
Frequently asked questions
Can a classic theme still be used on a current WordPress site?
Yes. Classic themes remain supported, and many sites still run them. The block editor works with classic themes for writing posts and pages. The site editor, however, is only available with block themes, so classic themes keep their existing layout tools.
Do I need to know PHP to use a block theme?
Not for everyday editing. Changing text, images, navigation and templates can all be done in the site editor. Code knowledge still helps for advanced work such as custom block styles, theme.json settings or building a theme from scratch.