What Is a WordPress Theme Builder?
A theme builder extends visual editing beyond individual pages so you can design repeatable site parts and assign them to content using conditions.
Pages are not the whole website
A normal page editor handles the content of individual pages. A theme builder addresses repeating site structures: headers, footers, post templates, archives and other layouts that need to apply across many URLs.
Elementor's model
Elementor describes Theme Builder as a system for creating site-part templates that can override aspects of the active WordPress theme's hierarchy, layout and styling. Current documentation includes headers, footers, global pages/posts, archives and WooCommerce templates.
Why conditions matter
Template conditions determine where a site part appears. A single-post template might apply to every article, while another could apply only to a specific category. Document these rules so future editors understand why a template is appearing.
When you may not need one
If your theme already gives you the site-wide layouts you need and your content structure is simple, another template layer may add unnecessary complexity. Use a theme builder when the control it adds solves a real design or publishing requirement.