The layout file contains the general HTML markup shared by all pages, and hence defines the HTML structure for the entire site. The layout relies on commands such as @RENDER section to place content defined by other pages in the structure defined. Of course, layout pages are just pages! Therefore, anything you can do in pages is allowed in layout files, too. No restrictions apply.
Once a layout is defined, pages reference the layout and supply content for the sections defined within the layout, including the body section. The following is a basic content page that refers to the basic-layout.layout file.

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