HTML5 is a core technology markup language of the
Internet used for structuring and presenting content for the World Wide Web. As
of October 2014 this is the final and
complete fifth revision of the HTML standard of the World Wide Web Consortium
(W3C). The previous version, HTML 4, was standardized in 1997.
Its core aims have been to improve the language with
support for the latest multimedia while keeping it easily readable by humans
and consistently understood by computers and devices (Web Browsers, Parser
etc.). HTML5 is intended to subsume not only HTML4 but also XHTML 1and DOM
Level 2 HTML.
Web Development is of at most importance as it is the
process of building a website. It comprises of designing, coding, and
maintenance. Since Internet started to dominate the world culture, business
habit, academic and many other things, it has become a trend and a necessity to
own a website. The site is a basic minimum requirement to have a online
presence. As online presence also means a functional gains.It is not a choice
to have a website.
HTML4, the popular HTML is still mostly used for web
programming but it is quickly getting replaced by all new HTML5. HTML4 was
introduced in 1999 which makes it a decade old technology and often unsuitable
for modern needs. Developed by World Wide Web Consortium (W3C) and the Web
Hypertext Application Technology Working Group (WHATWG) together, this attempts
to bridge the gap between the web development needs and technology available.
Let us point out to a few new trends which HTML5 has
brought forth.
General Differences between HTML5 and HTML4
Following are some of the major characteristics that
distinguish HTML5 from HTML4
1. Simplified and Clear Syntax
The syntax in HTML5 is extremely clear and simple as
compared to HTML4. One example of this is the DOCTYPE element. In HTML4 the
DOCTYPE declaration was too messy and lengthy and used to refer an external
source. However in HTML5 DOCTYPE element has been made extremely simple. For
instance a mere <!DOCTYPE html> is enough to specify the document type.
2.More Descriptive Schematics
The original goal of HTML was to develop a language
that could describe the structure of a document. As the web grew, developers
realized that oftentimes they were describing the same types of elements. For
example...a header, a footer, nav, articles, sections, etc. HTML5 recognizes
where the language has developed and incorporates those elements into the
language with new tags for that type of content.
3. Multimedia Elements
HTML5 contains built in support for integrated
multimedia files into web page via video and audio tags. Previously, in HTML4,
the multimedia content was integrated in web pages via third party plugins such
as Silverlight and flash.
4. Accessing User Geographical location
Previously in HTML4, it was an extremely cumbersome
task to get the geographical locations of the visitors visiting the site. It
was even difficult when the website was accessed through mobile devices. On the
other hand, in HTML5 is extremely easy to get the user location. HTML5’s JS GeoLocation can be
leveraged to identify the location of the user accessing the website.
5. Client Side storage
In HTML4, in order to store important data on client
side, browser’s cache was used. However,
that cache is limited and doesn’t support relational storage mechanism. In HTML5, this
issue has been addressed via Web SQL database and application cache that can be
access via HTML5’s JavaScript interface.
6. Client Server Communication
In HTML4 the communication between the client and
server was done through streaming and long polling, since there are no web
sockets available in HTML4. On the contrary, HTML5 contains web sockets that
allow full duplex communication between clients and servers.
7. JavaScript Threading Mechanism
In HTML4, JavaScript and
the browser interface with which user interacts, run in the same thread which
affects performance. HTML5 contains JS Web Worker API which allows JavaScript
and Browser interface to run in separate threads
8. Browser Compatibility
As mentioned, HTML4 is an
established standard for developing browser applications and has been in use
for more than 10 years. For this reason, HTML4 is compatible with almost all
web-browsers. On the other hand, HTML5 is still in the process of evolution and
the currently available tags are being modified and also new tags are being
added. Therefore, HTML5 lags behind HTML4 in terms of compatibility with the
browsers.
HTML5 comes with some major improvements. Some of them
are as follows.
- HTML, CSS, DOM and Javascript based new features.
- Improved image, video and audio handling.
- Self dependent error handling.
- Device
independent setting enabling universal access
- Scripting is replaced using
markups
HTML5 Browser Support
Often We have seen that our effort has no any value, when
the browser doesn’t support the element of HTML5. Somehow most of the updated
browsers are supporting the HTML5 element, But still this is a huge problem for
individuals to play with HTML5 on all of Internet browsers.
At the initial stage of HTML5
development very few browsers were able to display the data properly. But now
by dint of days and nights toil of various HTML5 development platforms, the
most updated browsers are supporting HTML5 tags or elements.
Still the main issue with Internet Explorer, which is
suffering from not proper rendering. Although Microsoft has lunched the 11th
version also, and a working draft has been introduced of 12th version also. But
still HTML5 is running with more advance features and that’s not compatible
with old browsers.
Below is chart showing the ratings for HTML5 browser
compatibility or support
HTML5 Best Practices
- Minimize HTTP requests a)CSS
Sprites b)Image Mapping c)Inline Images
- Add Expire Use of content delivery
network(CDN).
- ES or cache-controlled header
- Style sheets on the top and
Scripts at the bottom.
- Avoid CSS expressions
- Make JavaScript and CSS external
file
- Reduce DNS lookup
- Minify JavaScript and CSS files
- Avoid redirects
- Avoid nested tables
- Preload Components
- Reduce the number of DOM elements
- Minimize the usage of the number of Iframes
- Make Ajax cacheable
The technology is evolving as well, From the static
webpages built in HTML, now we are having responsive websites, which can
reshape itself intelligently depending on the devices which are fetching them,
built using "fluid grid technology
These Improvements are huge and when implemented
fully, these are expected to change the way the web development is done. As
most of the companies are adopting and welcoming the new technology. We can
surely hope for a better future which a cumulative effort can bring
HTML5 is an emerging standard of web development which is
getting quickly popular among web developers and users alike. The inbuilt
features make it much more suitable to address the needs of present day
computing which is not well handled by old HTML4.