New Elements in HTML5

<article> Defines an article in a document
<aside> Defines content aside from the page content
<bdi> Isolates a part of text that might be formatted in a different direction from other text outside it
<details> Defines additional details that the user can view or hide
<dialog> Defines a dialog box or window
<figcaption> Defines a caption for a <figure> element
<figure> Defines self-contained content
<footer> Defines a footer for a document or section
<header> Defines a header for a document or section
<main> Defines the main content of a document
<mark> Defines marked/highlighted text
<menuitem> Defines a command/menu item that the user can invoke from a popup menu
<meter> Defines a scalar measurement within a known range (a gauge)
<nav> Defines navigation links
<progress> Represents the progress of a task
<rp> Defines what to show in browsers that do not support ruby annotations
<rt> Defines an explanation/pronunciation of characters (for East Asian typography)
<ruby> Defines a ruby annotation (for East Asian typography)
<section> Defines a section in a document
<summary> Defines a visible heading for a <details> element
<time> Defines a date/time
<wbr> Defines a possible line-break