For many years, the Gutenberg editor was mainly used for the content of posts and pages, while headers, footers and layouts were controlled by the theme and the Customizer. Full site editing changed that. With a block theme, the same blocks you use to write a post can also be used to build the header, the footer, the blog archive and even the 404 page. If you have only worked with classic themes, the new approach can feel unfamiliar at first, so here is a beginner friendly overview.
Classic Themes and Block Themes
A classic theme builds its pages from PHP template files. You can change some things through the Customizer, widgets and menus, but larger layout changes usually mean editing code or using a page builder.
A block theme is built from block templates instead. Every part of the page is made of blocks, and you can edit all of it visually in the Site Editor, found under Appearance, then Editor. WordPress introduced this way of working in version 5.9 together with the Twenty Twenty-Two default theme, and every default theme since then has been a block theme.
If you are still deciding which theme to use, our guide on how to choose the right WordPress theme for your business covers what to look for beyond the design.
Templates and Template Parts
In the Site Editor you will find templates and template parts. A template controls the layout of a type of page. Typical templates include:
- a single post template for individual blog posts
- a page template for static pages
- an archive or index template for lists of posts
- a 404 template for pages that cannot be found
Template parts are smaller pieces that are shared between templates, most often the header and the footer. Edit the header template part once, and the change appears on every template that uses it. This works in a similar way to synced patterns, but for the structure of the site rather than its content.
Global Styles and theme.json
Block themes manage design settings through global styles. In the Site Editor you can open the Styles panel and change colours, typography, spacing and layout widths for the whole site, or for specific block types. Many themes also include style variations, which are ready-made combinations of colours and fonts that you can switch between with one click.
Behind the scenes, these settings live in a file called theme.json. It defines the colour palette, font sizes, spacing scale and which design options are available to editors. Developers can use it to keep a site consistent, for example by limiting the palette to brand colours so content editors cannot pick random shades. For more on adjusting a theme's look, see our post on theme customization.
Getting Started Safely
The Site Editor is powerful, and that also means it is easy to change more than you intended. A few habits make the learning curve gentler:
- Try things out on a staging site or a local install before you touch a live website.
- Make a full backup before larger changes to templates or global styles.
- Change one template at a time and check the result on the front end, on both desktop and mobile.
- Remember that customised templates can be reset to the theme's original version if something goes wrong.
The Site Editor can also export your theme, including your template changes, as a zip file. That is useful as an extra backup or when you want to move the design to another site.
Is a Block Theme Right for You?
Block themes are a good fit if you want to control the whole site with the tools you already know from the post editor, without relying on a separate page builder. They tend to load fewer scripts, which helps with speed, and they follow the direction WordPress itself is moving in.
Classic themes are still supported and remain a sensible choice if your site depends on a theme or plugin that has not adopted blocks yet. There is no need to switch an existing, well working site in a hurry. For new projects, though, it is worth giving a block theme a serious look.
Final Thoughts
Full site editing brings the block editor to every part of your website. Once you understand templates, template parts and global styles, building and adjusting layouts becomes much more direct. Start small, keep backups, and you will quickly feel at home in the Site Editor.