Defining Sections in HTML5
16 / 09 / 2015
All content lying inside the <body> element is part of a section. Sections in HTML5 can be nested. Beside the main section, defined by the <body> element, section limits are defined either explicitly or implicitly. Explicitly-defined sections are the content within <body>, <section>, <article>, <aside>, and <nav> tags.
Note: Each section can have its own heading hierarchy. Therefore, even a nested section can have an <h1>. See Defining Headings in HTML5.
Example: