With Footer and Page Title Bar Layout Sections, you will find the full range of Design Elements, with which to design your content. But with Content Layout Sections, you will find a range of new Elements, in their own tab, called Layout Section Elements. For full details on this please see Avada Design Elements vs. Layout Elements, but in short, these Elements allow you to add dynamic content in the Content Layout Section, such as blog posts, portfolio items, author information, related posts, and more. You can also use the normal Design Elements when designing your Content Layout Sections, and as mentioned, these Layout Elements are only found in the Content Layout Section, where you need to display content from blog posts, archives, portfolio posts etc.