As you know, the builder is the foundation and themes are the design. Magento Frontend Builder lets you design any layout that you can imagine, bring it to life using the drag & drop interface, and watch it come to life right in front of your eyes with live preview. Magento Builder currently is a powerful tool for Magento developers to design & develop Magento websites. With a wide range of elements available, developers can create stunning features for the website to meet & fit any kind of the business you’re targeting with a peace of mind. So, it totally helps you save much time & money.
Magento Frontend Builder is a front-end Magento pages builder. It allows you build the page directly on the page, not in the admin panel, therefore allows you to view exactly which you want to build and change with live feedback on every change you make. You can build pages without coding with Magento Frontend Builder: https://www.magesolution.com/mgs-frontend-builder-theme.html