What is the difference between theme and page builder?
A theme in Shopify is the template code that determines how your website is presented. It allows you to change some specific settings of your store with the theme editor. If your theme doesn't have a setting for the change you want to make, you will need to edit the theme code.
By using page-builders, you can build and customize pages on your stores without the use of code. Additionally, rather than using a specific layout from a theme, you will have control over your design. Page builders like GemPages give you access to an effortless drag & drop editor. Instead of changing theme settings or adding lines of code to the backend, all you have to do is drag & drop different elements to the position you wish.
How does GemPages work with my theme?
Even when using GemPages, you need to have a theme published. The Header, Footer, and Navigation bar are still managed by your theme. What GemPages essentially does is help you modify the body section - the content between the Header and Footer. With GemPages, you can even choose to hide the Header and Footer from your theme.
When GemPages is installed and used on a store, it generates codes into your theme. A quick way to check is to go to Shopify Admin > Online Store > Theme > Actions > Edit Code and open the theme.liquid file. You'll see the two codes below:
When a page is created by GemPages, it is synced with Shopify’s backend, and a code template is created accordingly. After that, when you make any changes to the template from the Editor, GemPages will automatically modify the code for you.
What happens when I change the theme?
When you publish a new Shopify theme, all your created pages with GemPages will be automatically transferred over to the new theme.