Flow content is an HTML5 category that corresponds to the HTML categories Block-level elements and Inline elements. It contains all elements that are allowed as a direct child of the
<body> element. Elements belonging to the flow content category also contain text or embedded content.
Examples of elements that are not flow content, are
<head> (because it is a document structure element),
<meta> (because it is an
<head>-only element) and
<td> (because it is only allowed as descendant of