Page Builder supports a post type called Block. Basically, a Block is embedded content, it can be built by the Page Builder to insert under a shortcode or a widget into anywhere from your site.
To create a Block, navigate to Admin Dashboard → Block → Add New, then fill the Block’s name into the Title Field. Finally, turn on the Page Builder swicher (in the case you want).
Blocks can be embedded into your pages under Shortcodes or Widgets from Builder Systems. Blocks can be very useful when you want to build a fixed content for your site like sidebars or footers.