HTML elements or tags are used to define the content and meaning of a HTML document. Elements represent things; that is, they have intrinsic meaning, also known as semantics.
There are two types of elements normal and void. Tags which wrap around content using opening and closing tags are considered normal. Void or self-closing tags are expressed with a single tag. They do not wrap content because they have no end tag. The “/” is completely optional, so
<img/> is not different from
<img></img> is invalid.
area, base, br, col, command, embed, hr, img, input, keygen, link, meta, param, source, track, wbr.
The main tag can only be used once per page and it can not be a descendant of an <article>, <aside>, <footer>, <header>, or <nav> element. According to caniuse.com IE11 does not currently support the main element, but use of the HTML5 Shiv will fix this.
– [main element (w3schools.com)](https://www.w3schools.com/tags/tag_main.asp “A link to more resources.”)
The <article> element should contain a piece of self-contained content that could be distributed outside the context of the page. This includes things like news articles, blog posts, or user comments.
**More Blockquote Resources**
– [Blockquotes (alistapart.com)](https://gist.github.com/murtaugh/4489740 “A link to more resources.”)
<table> <thead> <tr> <th>Product</th> <th>Description</th> <th>Price</th> </tr> </thead> <tbody> <tr> <td>Pen</td> <td>A nice ball point pen.</td> <td>$2.50</td> </tr> <tr> <td>Paper</td> <td>A package of top-shelf paper.</td> <td>$4.99</td> </tr> <tr> <td>Stapler</td> <td>Sturdy and powerful stapler</td> <td>$3.00</td> </tr> <tbody> <tfoot> <tr> <td></td> <td>Total:</td> <td>$10.49</td> </tr> </tfoot> </table>
The header element is not sectioning content; it doesn’t introduce a new section in a document outline.
The nav element is intended to contain links to other pages within the site. Links to external sites is discouraged. Optionally nav tags can be put inside header tags.
The Inline Frame Element
<iframe> represents a nested browsing context, effectively embedding another HTML page into the current page.