HTML evolved a lot since last time I learned it. So this is a time to review what has changed since then.

What is new, what was removed in HTML5?

Deprecated.

In older HTML versions, several tags and attributes were used to style documents. These tags and attributes are not supported in HTML5!

Deprecated tags are font, center, and strike. No further usage of color and bgcolor attributes.

Charset

There are differences with charset declaration.

For HTML4

<meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1">

For HTML5

<meta charset="UTF-8">

New

What is new at w3schools.

Website Layout

HTML5 offers new semantic elements to support website layout. More details on w3schools.com.

Yes, the layout is rather broad subject but this is about HTML5. It is enough to say it has introduced following tags to clarify and support page layout. The following tags are now available:

header description
nav container for navigation links
section section in a document
article an idependent self-contained article
aside content aside from the content (a sidebar)
footer for the document or section
details additional details
summary heading for details element

Flex and Grid Layouts

  1. Flex Box Layout
  2. Grid Layout

Tables enhancement

I am not sure if it is HTML5 which introduced tags like caption, colgroup, col, thead, tbody, tfoot, but I do not recall seeing them in HTML before. They are briefly described by w3schools.

<mark> for marking

Not marked. <mark>Marked.</mark> Not marked.

Results:

Not marked. Marked. Not marked.

<abbr> for abbreviation

 <p>The <abbr title="World Health Organization">WHO</abbr> was founded in 1948.</p>

Results:

The WHO was founded in 1948.

Forms

I was also not aware of fieldset and legend tags. When were they introduced? It was not HTML5 which added them. More details on w3schools.

Personal information: First name:

Last name:



There are other tags, HTML5 specific, like datalist, keygen, output. The tag output seems to be particularly interesting because it allows to create highly interactive pages.

HTML5 added several new input types:

  • color FFCH
  • date nFFCH
  • datetime nFFnCH
  • datetime-local nFFCH
  • email FF
  • month
  • number
  • range FFCH
  • search
  • tel
  • time
  • url FireFox
  • week

There are also new input restrictions added. W3schools has details.

Input fields can have various attributes like value (initial value), readonly, disabled, size (in chars), maxlength. HTML5 has added a long list of attributes and among interesting are pattern (regexp to validate a field), placeholder, required.