HEADER
- element represents a container for introductory content or a set of navigational links. A <header> element typically.
BODY
- <body> element contains all the contents of an HTML document, such as text, hyperlinks, images, tables, lists, etc.
-In computing, a sidebar is a user interface element that displays a list of choices. It typically appears as a column to the left of the main content, though it can appear on the right side as well. ... Word processors
FOOTER