A typical web page has headers, footers, navigation, central area and side bars. Now if we want to represent the same in HTML 4 with proper names to the HTML section we would probably use a DIV tag.

But in HTML 5 they have made it more clear by creating element names for those sections which makes your HTML more readable.

More details:

★ <header>: Represents header data of HTML.

★ <footer>: Footer section of the page.

★ <nav>: Navigation elements in the page.

★ <article>: Self-contained content.

★ <section>: Used inside article to define sections or group content in to sections.

★ <aside>: Represent side bar contents of a page.