What does HTML5 mean for websites and web applications?
The W3C is the governing body for web standards, HTML5 being the most recent for delivering websites and web applications.
To make matters a little confusing, HTML5 actually covers a variety of technologies - not just HTML, but hopefully we can demystify it for you.
HTML markup itself
Semantic elements such as
<nav> have been added to the specification, this means that browsers and other computer programs can more easily target specific bits of websites - a great example of this is Safari's Reader feature which extracts articles from the page and isolates them. As more content aggregators and web services adopt these new standards in their parsing, it'll be easier for them to pull in data and articles from your public-facing websites.
Other changes to the markup include additional attributes which will allow easy addition of more advanced form functionality, such as marking a field as specifically for email addresses (which will also pull up a keyboard with the @ symbol visible on iOS devices) or setting the focus to a particular field on when the page is loaded. The benefits of these attributes lie in the speed of development for web applications, and the usability improvements for users.
If you take a look at the code behind our site - you might notice we make use of quite a few of these elements and attributes.
Standardised video & audio
Rendering video or audio players is a real pain, usually involving code spaghetti and a mismatch of Flash, Quicktime etc, thankfully HTML5 will provide a consistent manner in which to embed and even customise players. If your website or app uses video, you can look forward to less headaches from users of different platforms and hardware acceleration to increase performance.
Previously a maintained two-way connection for communication between web pages and servers wasn't possible, so hacks (e.g. Comet) were employed to serve real-time needs. The trouble with these hacks is they weren't very performant, servers are much more comfortable with the new web-socket protocol, so it's possible to implement real-time updates, whether it's chatrooms, notifications or simple data updates more cheaply and with increased stability.
Offline browsing and local databases
As mobile browsing increases being able to browse the web and work with web applications despite lack of an active internet connection becomes increasingly important. HTML5 specifies a standard for caching data locally, and even creating databases so your app can continue to work and simply synchronise the changes once the internet connection is restored.
Geolocation & other contextual services
Again, responding to an increase in mobile browsing, the ability to know device specific information is opening up a whole new angle for websites. You can retrieve location, orientation and even access microphones to adjust the experience to specific user needs.
Mobiles aren't the only devices likely to get additional treatment, more and more people are browsing the web on their TVs via web-enabled devices such as Blu-Ray players and gaming consoles.