A theme builder, on the other hand, is a Joomla extension or feature that allows you to customize the overall look and layout of your Joomla website. You can use it to change various design elements, e.g. colors, fonts, styles, layouts and more. With a theme builder, you can create a consistent visual identity for your website and ensure that all pages conform to the defined theme settings. It provides a centralized platform to manage the overall look and feel of your Joomla site, making it easy to maintain and update the theme across multiple sites.