HTML5 - Quick Guide
HTML5 is the next major revision of the HTML standard superseding HTML 4.01, XHTML 1.0, and XHTML 1.1. HTML5 is a standard for structuring and presenting content on the World Wide Web.
The latest versions of Apple Safari, Google Chrome, Mozilla Firefox, and Opera all support many HTML5 features and Internet Explorer 9.0 will also have support for some HTML5 functionality.
HTML5 introduces a number of new elements and attributes that helps in building a modern websites. Following are great features introduced in HTML5.
New Semantic Elements: These are like <header>, <footer>, and <section>.
Forms 2.0: Improvements to HTML web forms where new attributes have been introduced for <input> tag.
Persistent Local Storage: To achieve without resorting to third-party plugins.
WebSocket : A a next-generation bidirectional communication technology for web applications.
Server-Sent Events: HTML5 introduces events which flow from web server to the web browsers and they are called Server-Sent Events (SSE).
Audio & Video: You can embed audio or video on your web pages without resorting to third-party plugins.
Geolocation: Now visitors can choose to share their physical location with your web application.
Microdata: This lets you create your own vocabularies beyond HTML5 and extend your web pages with custom semantics.
Drag and drop: Drag and drop the items from one location to another location on a the same webpage.
The HTML 5 language has a "custom" HTML syntax that is compatible with HTML 4 and XHTML1 documents published on the Web, but is not compatible with the more esoteric SGML features of HTML 4.
HTML 5 does not have the same syntax rules as XHTML where we needed lower case tag names, quoting our attributes,an attribute had to have a value and to close all empty elements.
But HTML5 is coming with lots of flexibility and would support the followings:
Uppercase tag names.
Quotes are optional for attributes.
Attribute values are optional.
Closing empty elements are optional.
DOCTYPEs in older versions of HTML were longer because the HTML language was SGML based and therefore required a reference to a DTD.
HTML 5 authors would use simple syntax to specify DOCTYPE as follows:
All the above syntax is case-insensitive.
HTML 5 authors can use simple syntax to specify Character Encoding as follows:
All the above syntax is case-insensitive.
Elements are marked up using start tags and end tags. Tags are delimited using angle brackets with the tag name in between.
The difference between start tags and end tags is that the latter includes a slash before the tag name.
Following is the example of an HTML5 element:
HTML5 tag names are case insensitive and may be written in all uppercase or mixed case, although the most common convention is to stick with lowercase.
Most of the elements contain some content like <p>...</p> contains a paragraph. Some elements, however, are forbidden from containing any content at all and these are known as void elements. For example, br, hr, link and meta etc.
Here is a complete list of HTML5 Elements.
Elements may contain attributes that are used to set various properties of an element.
Some attributes are defined globally and can be used on any element, while others are defined for specific elements only. All attributes have a name and a value and look like as shown below in the example.
Following is the example of an HTML5 attributes which illustrates how to mark up a div element with an attribute named class using a value of "example":
Attributes may only be specified within start tags and must never be used in end tags.
HTML5 attributes are case insensitive and may be written in all uppercase or mixed case, although the most common convention is to stick with lowercase.
Here is a complete list of HTML5 Attributes.
Here is a complete list of HTML5 Events.
The following tags have been introduced for better structure:
section: This tag represents a generic document or application section. It can be used together with h1-h6 to indicate the document structure.
article: This tag represents an independent piece of content of a document, such as a blog entry or newspaper article.
aside: This tag represents a piece of content that is only slightly related to the rest of the page.
header: This tag represents the header of a section.
footer: This tag represents a footer for a section and can contain information about the author, copyright information, et cetera.
nav: This tag represents a section of the document intended for navigation.
dialog: This tag can be used to mark up a conversation.
figure: This tag can be used to associate a caption together with some embedded content, such as a graphic or video.
The markup for an HTM 5 document would look like the following:
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I understand you would not be satisfied with this quick guide, so I request to explore HTML5 Tutorial because it is a big change in HTML4 version and can not be covered in a short note.