To quickly understand and get started with this new feature, it’s useful to understand Layouts and Layout Sections and how they work together. For full details, please see Understanding Layouts & Layout Sections, but it is perhaps easiest to think of a Layout as simply a container that holds the page content. The content itself, however, comes from the Layout Sections. Together, you can consider them a template for how the page layout should look.
A layout is comprised of content coming from four layout sections: a Header Section, a Page Title Bar Section, a Content Section, and a Footer Section. This is how Avada is constructed, and normally, you set the content of the Layout Sections through the Options and the pages you build.
What Layouts allow you to do though, is to create and set your own Layouts throughout the theme. This can be done globally, by adding custom Layout Sections to the Global Layout, or you can create your own Conditional Layouts; for example, a Layout for single posts, 404 pages, or for Search Results, and then populate that Layout with custom Layout Sections.
The structure is a little bit like the Avada Slider, where you create a Slider, and then add slides to the slider. As seen below, you have a Global Layout and any created Layouts, and you can override any Layout Section with your own custom layout sections and create conditions for when those Layouts are used.